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1

Quantification of fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) in meconium for detection of alcohol abuse during pregnancy: Correlation study between both biomarkers.  

PubMed

This article presents results from 47 meconium samples, which were analyzed for fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) for detection of gestational alcohol consumption. A validated microwave assisted extraction (MAE) method in combination with GC-MS developed in the Institute of Forensic Science (Santiago de Compostela) was used for FAEE and the cumulative concentration of ethyl myristate, ethyl palmitate and ethyl stearate with a cut-off of 600ng/g was applied for interpretation. A simple method for identification and quantification of EtG has been evaluated by ultrasonication followed solid phase extraction (SPE). Successful validation parameters were obtained for both biochemical markers of alcohol intake. FAEE and EtG concentrations in meconium ranged between values lower than LOD and 32,892ng/g or 218ng/g respectively. We have analyzed FAEE and EtG in the same meconium aliquot, enabling comparison of the efficiency of gestational ethanol exposure detection. Certain agreement between the two biomarkers was found as they are both a very specific alcohol markers, making it a useful analysis for confirmation. PMID:25137651

Cabarcos, Pamela; Tabernero, María Jesús; Otero, José Luís; Míguez, Martha; Bermejo, Ana María; Martello, Simona; De Giovanni, Nadia; Chiarotti, Marcello

2014-11-01

2

Quantification of fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) in meconium from newborns for detection of alcohol abuse in a maternal health evaluation study.  

PubMed

Fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) were determined in 602 meconium samples in a maternal health evaluation study for detection of gestational alcohol consumption. A validated headspace solid phase microextraction method in combination with GC-MS was used for FAEE and the cumulative concentration of ethyl palmitate, ethyl linoleate, ethyl oleate, and ethyl stearate with a cut-off of 500 ng/g was applied for interpretation. A new and simple method was developed and validated for quantification of EtG from 10-20 mg meconium with D(5)-EtG as internal standard consisting of 30 min. extraction with methanol/water (1:1, v/v), evaporation of methanol, filtration of the aqueous solution through a cellulose filter and injection into LC-MS-MS. The limits of detection and quantification for EtG were 10 and 30 ng/g, the recovery 86.6 to 106.4% and the standard deviation of the concentrations ranged from 13% at 37 ng/g to 5% at 46,700 ng/g (N = 6). FAEE above the cut-off were found in 43 cases (7.1%) with cumulative concentrations between 507 and 22,580 ng/g and with one outlier of about 150,000 ng/g (EtG not detected). EtG was detected in 97 cases (16.3%) and concentrations between LOD and 10,200 ng/g with another outlier of 82,000 ng/g (FAEE 10,500 ng/g). Optimal agreement between the two markers was obtained with a cut-off for EtG of 274 ng/g and 547 cases with both FAEE- and EtG-negative, 33 cases with both FAEE- and EtG-positive, nine cases with FAEE-positive and EtG-negative, and seven cases with FAEE-negative and EtG-positive. Differences in physical, chemical, and biochemical properties and in the pharmacokinetic behavior are discussed as reasons for the deviating cases. In none of the 602 cases, serious alcohol consumption was reported by the mothers and no evidence for gestational ethanol exposure was observed in the medical investigation of the newborns. It is concluded that the combined use of FAEE and EtG in meconium as markers for fetal alcohol exposure essentially increases the accuracy of the interpretation and helps to avoid false positive and false-negative results. PMID:20145912

Bakdash, Abdulsallam; Burger, Pascal; Goecke, Tamme W; Fasching, Peter A; Reulbach, Udo; Bleich, Stefan; Hastedt, Martin; Rothe, Michael; Beckmann, Matthias W; Pragst, Fritz; Kornhuber, Johannes

2010-04-01

3

A pharmacokinetic study of ethyl glucuronide in blood and urine: Applications to forensic toxicology  

Microsoft Academic Search

This pharmacokinetic study investigated the kinetics of ethanol and its metabolite ethyl glucuronide (EtG) in blood and urine during the whole time course of absorption and elimination. There are few previous studies on the kinetics of EtG in blood, and we wanted to evaluate whether such knowledge could yield valuable information regarding the time of ethanol ingestion in forensic cases,

Gudrun Høiseth; Jean Paul Bernard; Ritva Karinen; Lene Johnsen; Anders Helander; Asbjørg S. Christophersen; Jørg Mørland

2007-01-01

4

Markers of chronic alcohol use in hair: Comparison of ethyl glucuronide and cocaethylene in cocaine users  

Microsoft Academic Search

Two direct ethanol metabolites, namely ethyl glucuronide (EtG) and cocaethylene (CE), in the hair of cocaine (COC) users were compared in this study.Hair samples (n=68) were submitted to the determination of EtG (by liquid chromatography-electrospray-tandem mass spectrometry) and of COC and metabolites, including CE (by gas chromatography-mass spectrometry). Quantitative and qualitative results were compared.No quantitative correlation was found between EtG

Lucia Politi; Alessandra Zucchella; Luca Morini; Cristiana Stramesi; Aldo Polettini

2007-01-01

5

Testing for ethanol markers in hair: Discrepancies after simultaneous quantification of ethyl glucuronide and fatty acid ethyl esters.  

PubMed

The hair of 97 cases were analysed for ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEE, including ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate) according to the Society of Hair Testing guidelines to examine the role of both tests in documenting chronic excessive alcohol drinking, particularly when the results are in contradiction. 27 (27.8%) results were EtG negative and FAEE positive, when applying the SoHT cut-offs, probably due to the use of alcohol-containing hair products. Four cases (4.1%) were EtG positive and FAEE negative that were attributed to the use of herbal lotions containing EtG. PMID:24794020

Kintz, P; Nicholson, D

2014-10-01

6

Examination of sex differences in fatty acid ethyl ester and ethyl glucuronide hair analysis.  

PubMed

Clinical studies examining performance of fatty acid ethyl esters (FAEE) and ethyl glucuronide (EtG) in identifying excessive alcohol consumption have been primarily conducted in male populations. An impact of hair cosmetics in producing both false-negative EtG results and false-positive FAEE results has been demonstrated, suggesting a possible bias in female populations. This study evaluates FAEE-positive hair samples (>0.50?ng/mg) from n?=?199 female and n?=?73 male subjects for EtG. Higher FAEE/EtG concordance was observed amongst male over female subjects. Performance of multiple proposed EtG cut-off levels were assessed; amongst female samples, FAEE/EtG concordance was 36.2% (30?pg/mg), 36.7% (27?pg/mg), and 43.7% (20?pg/mg). Non-coloured hair demonstrated a two-fold increase in concordance (41.8 v. 20.8%) over coloured hair in the female cohort. FAEE levels did not differ between male and female subjects; however they were lower in coloured samples (p?=?0.046). EtG was lower in female subjects (p?=?0.019) and coloured samples (p?=?0.026). A total of n?=?111 female samples were discordant. Amongst discordant samples (EtG-negative), 26% had evidence of recent alcohol use including consultation histories (n?=?20) and detectable cocaethylene (n?=?9); 29% of discordant samples were coloured. False-negative risk with ethyl glucuronide analysis in females was mediated by cosmetic colouring. These findings suggest that combined analysis of FAEE and EtG is optimal when assessing a female population and an EtG cut-off of 20?pg/mg is warranted when using combined analysis. While concordant FAEE/EtG-positive findings constitute clear evidence, discordant FAEE/EtG findings should still be considered suggestive evidence of chronic excessive alcohol consumption. PMID:24817046

Gareri, Joey; Rao, Chitra; Koren, Gideon

2014-06-01

7

Voucher-Based Reinforcement for Alcohol Abstinence Using the Ethyl-Glucuronide Alcohol Biomarker  

ERIC Educational Resources Information Center

This study assessed the effects of a contingency management (CM) intervention for alcohol consumption in 10 alcohol-dependent participants. An ABCA design was used. Vouchers were provided contingent on results of ethyl glucuronide (EtG) urine tests (an alcohol biomarker with a 2-day detection period) and alcohol breath tests during the C phase.…

McDonell, Michael G.; Howell, Donelle N,; McPherson, Sterling; Cameron, Jennifer M.; Srebnik, Debra; Roll, John M.; Ries, Richard K.

2012-01-01

8

Practical experiences in application of hair fatty acid ethyl esters and ethyl glucuronide for detection of chronic alcohol abuse in forensic cases  

Microsoft Academic Search

This article presents results from 1872 hair samples, which were analyzed for fatty acid ethyl esters (FAEEs) and ethyl glucuronide (EtG). The results were evaluated in the context of self-reported drinking behavior, the use of hair cosmetics, the gender of the sample donors and hair sample length. For comparison, CDT and GGT in serum were available in 477 and 454

S. Suesse; F. Pragst; T. Mieczkowski; C. M. Selavka; A. Elian; H. Sachs; M. Hastedt; M. Rothe; J. Campbell

9

Markers of chronic alcohol use in hair: comparison of ethyl glucuronide and cocaethylene in cocaine users.  

PubMed

Two direct ethanol metabolites, namely ethyl glucuronide (EtG) and cocaethylene (CE), in the hair of cocaine (COC) users were compared in this study. Hair samples (n=68) were submitted to the determination of EtG (by liquid chromatography-electrospray-tandem mass spectrometry) and of COC and metabolites, including CE (by gas chromatography-mass spectrometry). Quantitative and qualitative results were compared. No quantitative correlation was found between EtG and CE, as well as between EtG and the cocaethylene concentration divided by the concentration of COC and its metabolites (benzoylecgonine and ecgonine methylester, as COC equivalents). Nevertheless, many factors are supposed to affect the amount of the two substances incorporated in the hair matrix, such as the subject's habits in ethanol and COC use, genetic variability in the metabolism of both substances, and the different chemical and physical properties of EtG and CE. When establishing a cut-off of 4 pg/mg for EtG and of 200 pg/mg for CE, 47 samples tested positive for EtG and 41 samples tested positive for CE; 12 samples out of the 47 EtG-positives tested negative for CE (25%), whereas 6 samples out of the 41 CE-positives tested negative for EtG (15%). According to these data, EtG appears to be a more sensitive and specific marker of non-moderate alcohol users than CE. PMID:17184945

Politi, Lucia; Zucchella, Alessandra; Morini, Luca; Stramesi, Cristiana; Polettini, Aldo

2007-10-01

10

Development and validation of a gas chromatography–negative chemical ionization tandem mass spectrometry method for the determination of ethyl glucuronide in hair and its application to forensic toxicology  

Microsoft Academic Search

Ethyl glucuronide (EtG) is a minor and direct metabolite of ethanol. EtG is incorporated into the growing hair allowing retrospective investigation of chronic alcohol abuse. In this study, we report the development and the validation of a method using gas chromatography–negative chemical ionization tandem mass spectrometry (GC–NCI-MS\\/MS) for the quantification of EtG in hair. EtG was extracted from about 30mg

Hicham Kharbouche; Frank Sporkert; Stéphanie Troxler; Marc Augsburger; Patrice Mangin; Christian Staub

2009-01-01

11

The influence of ethanol containing cosmetics on ethyl glucuronide concentration in hair.  

PubMed

Ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEE), non-volatile, direct metabolites of ethanol have been shown to be suitable markers for the evaluation of social and chronic excessive alcohol consumption. Previous investigations have shown that the regular use of hair-care products with high alcohol content lead to an increase of FAEE concentration and consequently gave false-positive results for the determination of FAEE in hair. In this study we investigated the influence of a long-term hair treatment with EtOH containing lotion, on the EtG concentrations in hair. In this study 7 volunteer subjects (classified as either rare, social or heavy drinkers) treated the right side of their scalp every day during a one or two month period with a commercial hair tonic (Seborin), which contains 44.0% ethanol (vol%). Collection of hair specimens from both sides of the scalp was done one day before hair treatment, one week and one month after treatment (for 5 subjects also after two months of treatment). A hair segment of 3 centimeters (cm) was cut and then washed with water and acetone, and then pulverized. EtG was quantified by GC/MS after pulverization and 2h of ultrasonication in water, extraction by solid phase extraction using Oasis MAX columns and derivatization with HFBA. Measurements were done in negative chemical ionization mode using EtG-D5 as internal standard. Comparison of EtG concentration in the treated and in the non-treated hair specimens did not show any increase at the different dates of collection for the 7 subjects. In conclusion, these results show that there is no indication for an increase of EtG after use of ethanol containing hair cosmetics. PMID:22051770

Martins Ferreira, Liliane; Binz, Tina; Yegles, Michel

2012-05-10

12

An evaluation of washing and extraction techniques in the analysis of ethyl glucuronide and fatty acid ethyl esters from hair samples.  

PubMed

Ethyl glucuronide (EtG) and fatty acid ethyl esters (FAEEs) are alcohol metabolites measured in hair and are after a decade of research thought to be the best markers in hair to indicate alcoholism and abstinence Forensic Sci. Int. 218 (2012) 2. A great body of work concerning EtG and FAEEs detection in hair has been performed. However, no recent extensive comparison has been made concerning washing and extraction procedures. This work shows that the washing procedure of dichloromethane followed by a methanol rinse of the hair sample removes more than 16% of the FAEEs and 50% of the total EtG that is present in and on the hair. A review of ten washing protocols (where the removal is categorised: high, medium or low) showed that a relatively high percentage of FAEEs was removed and "medium" amount of EtG compared to the other washing protocols. This work shows promising results for the extraction of the FAEEs and the combined extraction of FAEEs and EtG by using 30min of sonication with methanol. More FAEEs were recovered from hair with methanol than with any other extraction solvent including the commonly used dimethyl sulfoxide/heptane mixture. When the sonication time was increased a higher percentage of transesterification of the FAEEs was observed, the extraction was "dirtier" as solids and a colour change was observed whereas the extraction efficiency did not increase. Therefore, washing the hair sample with dichloromethane and methanol followed by an addition of 1ml of methanol and sonication for 30min to extract the FAEEs and EtG from hair is recommended for FAEEs as well as for the combined analysis of EtG and FAEEs. A linear calibration curve (r(2)>0.99) was obtained for all analytes. PMID:24590191

Bossers, L C A M; Paul, R; Berry, A J; Kingston, R; Middendorp, C; Guwy, A J

2014-03-15

13

Utility of urinary ethyl glucuronide analysis in post-mortem toxicology when investigating alcohol-related deaths.  

PubMed

Use and abuse of alcohol are common findings when unnatural deaths are investigated as evidenced by high blood- and urine- alcohol concentrations (BAC and UAC) at autopsy. Because ethanol is metabolized in the liver until the time of death, the autopsy BAC or UAC might be negative even though the deceased had consumed alcohol in the immediate ante-mortem period. Analysis of the non-oxidative metabolite of ethanol [ethyl glucuronide (EtG)] offers a more sensitive test of recent drinking. In this paper, we determined the concentrations of ethanol and EtG in urine samples from 972 consecutive forensic autopsies. In 425 cases (44%) both EtG and ethanol were positive, which supports ante-mortem drinking. In 342 cases (35%), both EtG and ethanol was negative, which speaks against any consumption of alcohol just before death. In 181 cases, ethanol was negative in urine (<0.2 g/kg), whereas EtG was positive (>0.5 mg/L), which points towards ingestion of alcohol some time before death. In these cases, mean and median concentrations of EtG were 53.2 mg/L and 23.7 mg/L, respectively, although there was no mention of alcohol on 131 of the death certificates. Alcohol was mentioned on death certificates as an underlying or immediate cause of death or a contributing factor in 435 (45%) cases, which rose to 566 (58%) cases when positive EtG results were included. This article demonstrates the usefulness of EtG analysis in routine post-mortem toxicology when ante-mortem drinking and alcohol-related deaths are investigated. PMID:24954799

Sundström, M; Jones, A W; Ojanperä, I

2014-08-01

14

Do drug users use less alcohol than non-drug users? A comparison of ethyl glucuronide concentrations in hair between the two groups in medico-legal cases  

Microsoft Academic Search

Two groups were selected from the remainder of hair samples that had been tested for drugs at TrichoTech for medico-legal cases: samples that tested negative (drug-negative group; N=42, age 33.4±7.2 years) and samples that tested positive for drugs (drug-positive group; N=57, age 32.5±8.8 years).A rapid, simple method to detect the ethanol metabolite, ethyl glucuronide (EtG) in hair has been developed.

Richard Paul; Robert Kingston; Lolita Tsanaclis; Anthony Berry; Alan Guwy

2008-01-01

15

Clinical Application of Ethyl Glucuronide Testing in the U.S. Army  

Microsoft Academic Search

This study examined the clinical characteristics of ethyl glucuronide testing among service members referred to a military substance abuse program. The authors analyzed 1,852 urine specimens from 328 service members collected over a two year period. Among all participants, approximately one-fifth (n = 45\\/262, 17.2%) produced a positive ethyl glucuronide result at the initial assessment. Nearly two-thirds (n = 29\\/45,

R. Gregory Lande; Barbara Marin; Audrey S. Chang

2010-01-01

16

Effect of bleaching on ethyl glucuronide in hair: An in vitro experiment  

Microsoft Academic Search

IntroductionEthyl glucuronide in hair (HEtG) has recently gained great attention, because of its high sensitivity and specificity in the diagnosis of chronic alcohol abuse. Due to its high polarity hydrophilicity, a strong hair treatment followed by a shampooing may lead to removal\\/degradation of this molecule from hair matrix.

Luca Morini; Alessandra Zucchella; Aldo Polettini; Lucia Politi; Angelo Groppi

2010-01-01

17

A SPME-GC/MS Procedure for the Determination of Fatty Acid Ethyl Esters in Hair for Confirmation of Abstinence Test Results.  

PubMed

Fatty acid ethyl esters (FAEE), direct metabolites of ethanol, are suitable alcohol markers that can be detected in different tissues. The determination of FAEE in hair can help to evaluate social and excessive alcohol consumption. Due to the presence of FAEE in the hair of teetotalers, proving alcohol abstinence seems to be impossible. To verify these results, an solid phase micro extraction-gas chromatography/mass spectrometry procedure for the determination of the four FAEE: ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate in hair was validated with special focus on low concentration levels. Besides very high sensitivity (limits of detection between 0.005 and 0.009 ng/mg), good results for linearity, precision and accuracy, recovery and stability were achieved. In addition, 73 hair samples with measured ethyl glucuronide (EtG) concentrations between 4 and 10 pg/mg were analyzed for FAEE. By using the following cut-offs: EtG: 7 pg/mg, FAEE: 0.2 ng/mg a satisfying matching rate of 72.6% was found. This shows that FAEE can be determined to verify borderline EtG concentrations even in the context of abstinence tests. However, the diversified influencing factors on analyte concentrations in hair, which may explain the large deviations between EtG and FAEE results observed in some cases, have to be mentioned when interpret ambiguous results. PMID:24125737

Albermann, Maria Elena; Madea, Burkhard; Musshoff, Frank

2014-10-01

18

Coupled ITG/TEM-ETG Gyrokinetic Simulations  

NASA Astrophysics Data System (ADS)

Electron temperature gradient (ETG) transport is conventionally defined as the electron energy transport from high-k where ions are adiabatic and there can be no ion energy or plasma transport. Previous simulations have assumed adiabatic ions (ETG-ai). However using the GYRO gyrokinetic code [1], we have found that many simulation cases with trapped electron at moderate shear do not nonlinearly saturate unless fully kinetic ions and some low-k ion scale zonal flow modes are included. We define high-k ETG-ki transport to be that arising from ky?s-i> 1 including electron gyroradius scales ky?s-e˜1, and ion temperature gradient and trapped electron mode (ITG/TEM) transport to be that from ky?s-i<=1. There has been speculation [2] that ETG transport could be modified by the nonlinear coupling to the ITG/TEM turbulence (or vise-versa). We have done very expensive high Reynold's number (k-max/k-min)^2(?s-i/?s-e)^2=2? high-resolution-large-flux-tube simulations with coupled ITG/TEM-ETG-ki turbulence. By comparing expensive simulations with much cheaper uncoupled high-resolution-small-flux-tube ETG-ki and low-resolution-large-flux-tube ITG/TEM simulations, we hope to demonstrate that superposition of the cheaper simulations is sufficiently accurate. Electron energy transport from ETG-ki is 5-10 fold smaller than from ITG/TEM except when the ExB shear is strong enough to quenched the low-k transport. GYRO compute time for the expensive simulations scales as ˜&3-4circ;. Reduced mass ratio ?=20 simulations have been done, and ?=30 simulations in progress accurately represent the ?=,40-60 physical range. 6pt [1] J. Candy and R.E. Waltz, Phys. Rev. Lett. 91 (2003) 045001. [2] C. Holland and P.H. Diamond, Phys. Plasmas 11 (2004) 1043.

Waltz, R. E.

2006-10-01

19

Nonlinear Saturation Physics of the ETG Modes  

NASA Astrophysics Data System (ADS)

Production and identification of electron temperature gradient (ETG) mode and the measurement of electron thermal conductivity due to it have been successfully done in a basic experiment in Columbia Linear Machine CLM [1,2]. Now we report the nonlinear saturation mechanism of the ETG modes. The bi-coherence experimental data shows coupling between two high frequency (˜2MHz) and one low frequency (˜40kHz) modes. The 3-wave coupling model (two radial harmonics ETG and one ion acoustic mode) yielded a theoretical saturation level of ETG mode ˜5 %, which roughly agrees with experiments. The role of ion acoustic mode in the saturation of ETG mode has also been experimentally demonstrated by using unique feedback techniques. This research was supported by U.S. Department of Energy Grant No. DE-FG02-98ER-54464. [4pt] [1] X.Wei, V.Sokolov, and A.K. Sen, Phys. Plasmas 17, 042108 (2010) [0pt] [2] V. Sokolov, A.K. Sen, APS DPP10, TP9.00022

Sokolov, Vladimir; Tokluoglu, E.; Sen, A. K.

2011-11-01

20

Experimental Investigation of the ETG Nonlinear Saturation Mechanism  

NASA Astrophysics Data System (ADS)

We have produced and identified the slab electron temperature gradient (ETG) mode in the Columbia Linear Machine (CLM) [1]. Now we investigate the nonlinear saturation mechanism of the ETG modes. We study 3-wave coupling physics via the bi- coherence investigation and find signatures of the interaction between ETG modes and some low frequency modes. The saturation mechanism of the ETG modes is suspected to be related to the damping of low frequency modes. More detailed identification of the low frequency modes including their dispersion will be reported. [4pt] [1] X. Wei, V. Sokolov, A.K. Sen, APS DPP08 TP6.00131

Wei, Xiao; Sokolov, Vladimir; Sen, Amiya K.

2009-11-01

21

Further Experimental Identification of ETG Modes  

NASA Astrophysics Data System (ADS)

The electron temperature gradient (ETG) mode, which is believed to be one of the strongest candidates for the anomalous electron energy transport [1, 2], is difficult to detect in experiments because of its high frequency (few MHz) and short wave length (k?e˜1). Using a DC bias heating scheme of the core plasma, we are able to produce sufficiently strong electron temperature gradient in Columbia Linear Machine (CLM). A high frequency mode at ˜2MHz, with azimuthal wave number m ˜15 , has been observed. This frequency is consistent with the result of a kinetic dispersion relation of slab ETG modes with appropriate E xB Doppler shift. The scaling of its fluctuation level with the temperature gradient scale length and the radial structure are found to be roughly consistent with theoretical expectations. The parallel wave number of the mode can be varied via changing the position of the endplate by at least 30 % and the scaling of the fluctuation level with k will also be reported. [1] W. Dorland et al., Phys. Rev. Lett. 85, 5579 (2000). [2] R.E. Waltz, J. Candy and M. Fahey, Phys. Plasmas, 14, 056116 (2007).

Wei, Xiao; Sokolov, Vladimir; Sen, Amiya K.

2008-11-01

22

Gyrokinetic Simulations of ETG and ITG Turbulence  

SciTech Connect

Published gyrokinetic continuum-code simulations indicated levels of the electron thermal conductivity {chi}{sub e} due to electron-temperature-gradient (ETG) turbulence large enough to be significant in some tokamaks, while subsequent global particle-in-cell (PIC) simulations gave significantly lower values. We have carried out an investigation of this discrepancy. We have reproduced the key features of the aforementioned PIC simulations using the flux-tube gyrokinetic PIC code, PG3EQ, thereby eliminating global effects and as the cause of the discrepancy. We show that the late-time low-transport state in both of these sets of PIC simulations is a result of discrete particle noise, which is a numerical artifact. Thus, the low value of {chi}{sub e} along with conclusions about anomalous transport drawn from these particular PIC simulations are unjustified. In our attempts to benchmark PIC and continuum codes for ETG turbulence at the plasma parameters used above, both produce very large intermittent transport. We have therefore undertaken benchmarks at an alternate reference point, magnetic shear s=0.1 instead of s=0.796, and have found that PIC and continuum codes reproduce the same transport levels. Scans in the magnetic shear show an abrupt transition to a high-{chi}{sub e} state as the shear is increased above s=0.4. When nonadiabatic ions are used, this abrupt transition is absent, and {chi}{sub e} increases gradually reaching values consistent with transport analyses of DIII-D, JET, and JT60-U discharges. New results on the balances of zonal-flow driving and damping terms in late-time quasi-steady ITG turbulence and on real-geometry gyrokinetic simulations of shaped DIII-D discharges are also reported.

Dimits, A; Nevins, W; Shumaker, D; Hammett, G; Dannert, T; Jenko, F; Dorland, W; Leboeuf, J; Rhodes, T; Candy, J; Estrada-Mila, C

2006-10-03

23

X-ray properties of optically selected ETGs (Danielson+, 2012)  

NASA Astrophysics Data System (ADS)

We study the X-ray properties of 393 optically selected early-type galaxies (ETGs) over the redshift range of z~~0.0-1.2 in the Chandra Deep Fields (CDFs). To measure the average X-ray properties of the ETG population, we use X-ray stacking analyses with a subset of 158 passive ETGs (148 of which were individually undetected in X-ray). This ETG subset was constructed to span the redshift ranges of z=0.1-1.2 in the ~~4Ms CDF-South and ~~2Ms CDF-North and z=0.1-0.6 in the ~~250ks Extended-CDF-South where the contribution from individually undetected active galactic nuclei (AGN) is expected to be negligible in our stacking. (2 data files).

Danielson, A. L. R.; Lehmer, B. D.; Alexander, D. M.; Brandt, W. N.; Luo, B.; Miller, N.; Xue, Y. Q.; Stott, J. P.

2012-11-01

24

Augmented LQG Optimal Control of Dynamic Performance for ETG System  

Microsoft Academic Search

Running of unstable speed exhaust turbine generator (ETG) using main engine (ME) waste heat by high turbulence intensities, in order to demand maximization of regenerative energy harvested from the ME waste heat and minimization of damage caused by mechanical losses and fatigue. ALQG control scheme for output power leveling with unknown dynamics is proposed in this paper. The control scheme

Gui-chen Zhang

2009-01-01

25

Autism and Phthalate Metabolite Glucuronidation  

ERIC Educational Resources Information Center

Exposure to environmental chemicals may precipitate autism spectrum disorders (ASD) in genetically susceptible children. Differences in the efficiency of the glucuronidation process may substantially modulate substrate concentrations and effects. To determine whether the efficiency of this pathway is compromised in children with ASD, we measured…

Stein, T. Peter; Schluter, Margaret D.; Steer, Robert A.; Ming, Xue

2013-01-01

26

Phenotype-genotype correlation of in vitro SN38 (active metabolite of irinotecan) and bilirubin glucuronidation in human liver tissue with UGT1A1 promoter polymorphism  

Microsoft Academic Search

Background: Hepatic uridine diphosphate glucuronosyltransferase (UGT) isoform 1A1 (UGT1A1) is primarily responsible for the glucuronidation of SN-38 (7-ethyl-10-hydroxycamptothecin), the active metabolite of the anticancer agent irinotecan. UGT1A1, also catalyzing the glucuronidation of bilirubin, has been shown to have reduced activity in Gilbert's syndrome. The presence of an additional TA repeat [(TA)7 TAA] in the TATA sequence of UGT1A1 has been

Lalitha Iyer; Diana Hall; Soma Das; Melissa A. Mortell; Jacqueline Ramírez; Sarang Kim; Anna Di Rienzo; Mark J. Ratain

1999-01-01

27

Simulations of ETG-driven turbulent transport in NSTX  

NASA Astrophysics Data System (ADS)

The gyrokinetic code GYRO [1] is used to simulate turbulent transport driven by ETG modes in two sets of conditions based on NSTX experiments. Many simulations are located at r/a=0.6 in a deuterium L-mode plasma with Te=1.1Ti, Zeff=1.5, q=1.3, and shear=1. We find that the experimentally determined ExB shearing rate controls the level of transport by limiting the size of the turbulent eddies. The ExB shearing rate removes the need to include modes with k??i< 1 in the simulation, thereby reducing the cost of using a gyrokinetic treatment for both electrons and ions and allowing simulations with mD/me up to 1600 that demonstrate convergence in this parameter. The ExB shear may also be responsible for the absence of runaway turbulence (previously reported by others for shear>0.4) in our simulations with adiabatic-ions. Preliminary work at r/a=0.34 in a helium L-mode plasma with Te=1.5Ti, Zeff=2.5, q=2.4, finds that the magnetic shear, s=-0.3, has a strong stabilizing influence. [1] J. Candy and R.E. Waltz, J. Comput. Phys. 186 (2003) 545

Mikkelsen, D. R.; Kaye, S. M.; Candy, J.; Waltz, R. E.

2008-11-01

28

Ethyl glucuronide and ethyl sulfate in autopsy samples 27 years after death  

Microsoft Academic Search

The unique case of a 50-year-old known alcoholic whose corpse was exhumed 27 years after death is reported. The man apparently\\u000a committed suicide by hanging, but many years later the case was questioned and homicide—linked to a long-lasting serial killer\\u000a case—was suspected. Thus, the corpse was exhumed, and at the autopsy it was found to be naturally mummified. This fact permitted

Lucia Politi; Luca Morini; Francesco Mari; Angelo Groppi; Elisabetta Bertol

2008-01-01

29

The UV window on counter rotating ETGs: insight from SPH simulations with chemo-photometric implementation  

E-print Network

The Galaxy Evolution Explorer (GALEX) detected ultraviolet emission in about 50% of multi-spin early-type galaxies (ETGs), suggesting the occurrence of a recent rejuvenation episode connected to the formation of these kinematical features. With the aim at investigating the complex evolutionary scenario leading to the formation of counter rotating ETGs (CR-ETGs) we use our Smooth Particle Hydrodynamic (SPH) code with chemo-photometric implementation. We discuss here the UV evolutionary path of two CR-ETGs, NGC 3593 and NGC 5173, concurrently best fitting their global observed properties, i.e., morphology, dynamics, as well as their total B-band absolute magnitude and spectral energy distribution (SED) extended over three orders of magnitude in wavelength. These simulations correspond to our predictions about the target evolution which we follow in the color-magnitude diagram (CMD), near-UV (NUV) versus r-band absolute magnitude, as a powerful diagnostic tool to emphasize rejuvenation episodes.

Bettoni, Daniela; Rampazzo, Roberto; Marino, Antonina; Galletta, Giuseppe; Buson, Lucio M

2014-01-01

30

The UV window on counter rotating ETGs: insight from SPH simulations with chemo-photometric implementation  

NASA Astrophysics Data System (ADS)

The Galaxy Evolution Explorer ( GALEX) detected ultraviolet emission in about 50 % of multi-spin early-type galaxies (ETGs), suggesting the occurrence of a recent rejuvenation episode connected to the formation of these kinematical features. With the aim at investigating the complex evolutionary scenario leading to the formation of counter rotating ETGs (CR-ETGs) we use our Smooth Particle Hydrodynamic (SPH) code with chemo-photometric implementation. We discuss here the UV evolutionary path of two CR-ETGs, NGC 3593 and NGC 5173, concurrently best fitting their global observed properties, i.e., morphology, dynamics, as well as their total B-band absolute magnitude and spectral energy distribution (SED) extended over three orders of magnitude in wavelength. These simulations correspond to our predictions about the target evolution which we follow in the color-magnitude diagram (CMD), near-UV (NUV) versus r-band absolute magnitude, as a powerful diagnostic tool to emphasize rejuvenation episodes.

Bettoni, D.; Mazzei, P.; Rampazzo, R.; Marino, A.; Galletta, G.; Buson, L. M.

2014-11-01

31

21 CFR 584.200 - Ethyl alcohol containing ethyl acetate.  

...2014-04-01 2014-04-01 false Ethyl alcohol containing ethyl acetate. 584.200...Affirmed as GRAS § 584.200 Ethyl alcohol containing ethyl acetate. The feed additive ethyl alcohol containing ethyl acetate meets the...

2014-04-01

32

A Preliminary Basic Experiment on the Production and Identification of Toroidal ETG Modes  

NASA Astrophysics Data System (ADS)

Production and identification of the slab branch of the Electron Temperature Gradient (ETG) mode and the measurement of the consequent electron thermal conductivity have been successfully made in a basic experiment in Columbia Linear Machine (CLM) [1,2]. A preliminary experiment on the transition of the slab mode to the toroidal (curvature) branch of ETG mode in CLM is reported. CLM was operated in the mirror configuration with cell length (50cm-100cm) and mirror ratio (1-2.2). The radius of curvature is Rc˜1.3m and the critical ratio for the transition to toroidal mode has been achieved, k| / 2 ?nk< 0.1 [3]. We first excite the slab ETG mode [1] and gradually increase the magnetic curvature drive by increasing the magnetic mirror ratio, and observe an increase of the ETG mode amplitude up to 2 times and a small change in mode frequency. Alternatively, we can shorten the mirror cell length via moving the mirror coil to increase the bounce average curvature drive and the mode amplitude. [4pt] [1] X.Wei, V.Sokolov, and A.K. Sen, Phys. Plasmas 17, 042108 (2010).[0pt] [2] V.Sokolov, and A.K. Sen, Phys. Rev. Lett. 107, 155001 (2011).[0pt] [3] J.Y.Kim and W.Horton, Phys.Fluids B 3, 1167 (1991).

Sokolov, Vladimir; Balbaky, Abed; Sen, Amiya K.

2012-10-01

33

Different Electrostatic Potentials Define ETGE and DLG Motifs as Hinge and Latch in Oxidative Stress Response?  

PubMed Central

Nrf2 is the regulator of the oxidative/electrophilic stress response. Its turnover is maintained by Keap1-mediated proteasomal degradation via a two-site substrate recognition mechanism in which two Nrf2-Keap1 binding sites form a hinge and latch. The E3 ligase adaptor Keap1 recognizes Nrf2 through its conserved ETGE and DLG motifs. In this study, we examined how the ETGE and DLG motifs bind to Keap1 in a very similar fashion but with different binding affinities by comparing the crystal complex of a Keap1-DC domain-DLG peptide with that of a Keap1-DC domain-ETGE peptide. We found that these two motifs interact with the same basic surface of either Keap1-DC domain of the Keap1 homodimer. The DLG motif works to correctly position the lysines within the Nrf2 Neh2 domain for efficient ubiquitination. Together with the results from calorimetric and functional studies, we conclude that different electrostatic potentials primarily define the ETGE and DLG motifs as a hinge and latch that senses the oxidative/electrophilic stress. PMID:17785452

Tong, Kit I.; Padmanabhan, Balasundaram; Kobayashi, Akira; Shang, Chengwei; Hirotsu, Yosuke; Yokoyama, Shigeyuki; Yamamoto, Masayuki

2007-01-01

34

UCRL-JRNL-227861 Gyrokinetic simulations of ETG and ITG turbulence  

E-print Network

particle-in-cell (PIC) simulations of electron-temperature-gradient (ETG) turbulence. Our investigations the effect on the linear growth rates is often modest. PACS codes: 52.65.Tt, 52.35.Ra, 52.25.Fi 1 measurements. Real geometry is found to have a significant effect on the transport rates, even though

Hammett, Greg

35

Inhibition of SN38 glucuronidation by ketoconazole  

Microsoft Academic Search

Background\\/Aims: Ketoconazole has been shown to inhibit the glucuronidation of the UGT2B7 substrates AZT and lorazepam. Its effect on UGT1A substrates is unknown. A recent study (Kehrer et al, JClin Oncol, 2002) found that co-administration of irinotecan and ketoconazole led to a significant increase in the formation of SN-38. This study investigates whether ketoconazole contributes to the increase in SN-38

W. Yong; J. Ramirez; F. Innocenti; M. J. Ratain

2005-01-01

36

A Basic Experiment on the Production and Identification of ETG Modes  

NASA Astrophysics Data System (ADS)

One of the strongest candidates for the anomalous electron energy transport is believed to be electron temperature gradient (ETG) mode [1, 2]. However, the high frequency (few MHz) and short wave length (k?e<1) make the direct observation of ETG modes difficult in experiments. Using a DC bias heating scheme of the core plasma, we are able to produce the drive parameter ?e= d ln Te / d ln n from 1 to 6 ( Te˜20 eV in the center and ˜1eV on the edge) in Columbia Linear Machine (CLM). A high frequency mode at ˜2MHz has been observed. Its azimuthal wave number in m ˜30 has been measured. These values are consistent with the results of a simple kinetic dispersion relation on appropriate E0 xB Doppler shift. The problem of the measurement of the small parallel wave number with the large azimuthal wave number has been resolved by a novel diagnostic method. The scaling of ETG fluctuation level versus ?e, as well as the radial structure of the mode will be reported. [1] W. Dorland et al., Phys. Rev. Lett. 85, 5579 (2000). [2] R.E. Waltz, J. Candy and M. Fahey, Phys. Plasmas 14, 056116 (2007).

Wei, Xiao; Sokolov, Vladimir; Sen, Amiya K.

2007-11-01

37

Conjugation position of quercetin glucuronides and effect on biological activity.  

PubMed

Quercetin glycosides are common dietary antioxidants. In general, however, potential biological effects of the circulating plasma metabolites (e.g., glucuronide conjugates) have not been measured. We have determined the rate of glucuronidation of quercetin at each position on the polyphenol ring by human liver cell-free extracts containing UDP-glucuronosyltransferases. The apparent affinity of UDP-glucuronosyltransferase followed the order 4'- > 3'- > 7- > 3, although the apparent maximum rate of formation was for the 7-position. The 5-position did not appear to be a site for conjugation. After isolation of individual glucuronides, the inhibition of xanthine oxidase and lipoxygenase were assessed. The K(i) for the inhibition of xanthine oxidase by quercetin glucuronides followed the order 4'- > 3'- > 7- > 3-, with quercetin-4'-glucuronide a particularly potent inhibitor (K(i) = 0. 25 microM). The glucuronides, with the exception of quercetin-3-glucuronide, were also inhibitors of lipoxygenase. Quercetin glucuronides are metabolites of quercetin in humans, and these compounds can retain some biological activity depending on conjugation position at expected plasma concentrations. PMID:11118813

Day, A J; Bao, Y; Morgan, M R; Williamson, G

2000-12-15

38

Curcumin Glucuronides: Assessing the Proliferative Activity against Human Cell Lines  

PubMed Central

A gram scale synthesis of the glucuronide metabolites of curcumin were completed in four steps. The newly synthesized curcumin glucuronide compounds 2 and 3 along with curcumin 1 were tested and their anti-proliferative effects against KBM-5, Jurkat cell, U266, and A549 cell lines were reported. Biological data revealed that as much as 1 ?M curcumin 1 exhibited anticancer activity and almost 100% cell kill was noted at 10 ?M on two out of four cell lines; while curcumin mono-glucuronide 2 as well as diglucuronide 3 displayed no suppression of cell proliferation. PMID:24280069

Pal, Ashutosh; Sung, Bokyung; Prasad, Basvoju A. Bhanu; Schuber, Paul T.; Prasad, Sahdeo; Aggarwal, Bharat B.; Bornmann, William G.

2014-01-01

39

Detection of pentachlorophenol and its glucuronide and sulfate conjugates in fish bile and exposure water  

SciTech Connect

The glucuronide and sulfate conjugates of pentachlorophenol (PCP) that were present in the bile and exposure water of goldfish (Carassius auratus) were used to develop methodology to quantify PCP and its metabolites. Reverse phase HPLC with radioactivity detection separated PCP and its metabolites, and was used to verify a method of quantification that used differential extraction and scintillation counting. Extractions of aqueous phase at pH 2 or 8, with butanol, ethyl acetate, or ether indicated that ether at pH 8 best separated PCP from its metabolites. The sulfate conjugate of PCP was the major metabolite produced when goldfish were exposed to 125 micrograms UC-PCP/l. It was present primarily in the exposure water, but also appeared in the bile.

Stehly, G.R.; Hayton, W.L.

1988-08-01

40

Impact of intestinal glucuronidation on the pharmacokinetics of raloxifene.  

PubMed

Raloxifene is extensively glucuronidated in humans, effectively reducing its oral bioavailability (2%). It was also reported to be glucuronidated in preclinical animals, but its effects on the oral bioavailability have not been fully elucidated. In the present study, raloxifene and its glucuronides in the portal and systemic blood were monitored in Gunn rats deficient in UDP-glucuronosyltransferase (UGT) 1A, Eisai hyperbilirubinemic rats (EHBRs), which hereditarily lack multidrug resistance-associated protein (MRP) 2, and wild-type rats after oral administration. The in vitro-in vivo correlation (IVIVC) of four UGT substrates (raloxifene, biochanin A, gemfibrozil, and mycophenolic acid) in rats was also evaluated. In Gunn rats, the product of fraction absorbed and intestinal availability and hepatic availability of raloxifene were 0.63 and 0.43, respectively; these values were twice those observed in wild-type Wistar rats, indicating that raloxifene was glucuronidated in both the liver and intestine. The ratio of glucuronides to unchanged drug in systemic blood was substantially higher in EHBRs (129-fold) than in the wild-type Sprague-Dawley rats (10-fold), suggesting the excretion of raloxifene glucuronides caused by MRP2. The IVIVC of the other UGT substrates in rats displayed a good relationship, but the oral clearance values of raloxifene and biochanin A, which were extensively glucuronidated by rat intestinal microsomes, were higher than the predicted clearances using rat liver microsomes, suggesting that intestinal metabolism may be a great contributor to the first-pass effect. Therefore, evaluation of intestinal and hepatic glucuronidation for new chemical entities is important to improve their pharmacokinetic profiles. PMID:21646435

Kosaka, Keigo; Sakai, Norifumi; Endo, Yuya; Fukuhara, Yuga; Tsuda-Tsukimoto, Minoru; Ohtsuka, Tatsuyuki; Kino, Ichiro; Tanimoto, Tomohiko; Takeba, Naomi; Takahashi, Masakatsu; Kume, Toshiyuki

2011-09-01

41

Measurement of Radial Electron Thermal Transport due to ETG Modes in a Basic Experiment  

NASA Astrophysics Data System (ADS)

Production and identification of electron temperature gradient (ETG) mode have been successfully demonstrated in a basic experiment in Columbia Linear Machine CLM [1]. Using a dc bias heating scheme of the core plasma, we are able to produce sufficiently strong ETG modes in CLM experiments. A unique miniature triple probe was used for local measurement of electron temperature and plasma potential fluctuations. Their cross-correlation yields the local radial electron thermal flux. A preliminary measurement of electron thermal conductivity indicates ?e is about ˜3 m^2/s ˜10 ?e,GB. This result appears to agree with a value of non-local thermal conductivity obtained from a rough theoretical estimation [2]. This research was supported by U.S. Department of Energy Grant No. DE-FG02-98ER-54464. [4pt] [1] X. Wei, V. Sokolov and A.K. Sen, Phys. Plasmas, 17, 042108 (2010). [0pt] [2] H.L. Berk et al, Nucl. Fusion, 33, 263 (1993).

Sokolov, Vladimir; Sen, Amiya

2010-11-01

42

Synthesis, hydrolysis and stability of psilocin glucuronide.  

PubMed

A two-step synthesis of psilocin glucuronide (PCG), the main metabolite of psilocin, with methyl 2,3,4-tri-O-isobutyryl-1-O-trichloroacetimidoyl-?-d-glucopyranuronate is reported. With the synthesized PCG, hydrolysis conditions in serum and urine were optimized. Escherichia coli proved to be a better enzyme source for ?-glucuronidase than Helix pomatia. It was essential to add ascorbic acid to serum samples to protect psilocin during incubation. Furthermore the stability of PCG and psilocin was compared as stability data are the basis for forensic interpretation of measurements. PCG showed a greater long-term stability after six months in deep frozen serum and urine samples than psilocin. The short-term stability of PCG for one week in whole blood at room temperature and in deep frozen samples was also better than that of psilocin. Therefore, PCG can be considered to be more stable than the labile psilocin and should always be included if psilocin is analyzed in samples. PMID:24513688

Martin, Rafaela; Schürenkamp, Jennifer; Pfeiffer, Heidi; Lehr, Matthias; Köhler, Helga

2014-04-01

43

Mangiferin glucuronidation: important hepatic modulation of antioxidant activity.  

PubMed

Mangiferin displays an extensive spectrum of pharmacological properties, including antioxidant activity. Its phase II metabolism in the presence of Aroclor 1254-induced and un-induced microsomal and cytosolic fractions from rat liver and the antioxidant potency of the glucuronidated conjugates were investigated. Mangiferin was not a substrate for the cytosolic sulphotransferases. Glucuronidation led to the formation of two monoglucuronidated metabolites of mangiferin and a monoglucuronidated metabolite of homomangiferin (a minor constituent of the mangiferin standard). Deconjugation utilising glucuronidase resulted in the disappearance of the metabolites, with the concomitant formation of the two parent compounds. Considering steric hinderance caused by the C-2 glucosyl moiety and the relative acidity of the xanthone OH groups, the 6-OH of mangiferin and, to a lesser degree the 7-OH, are likely to be the primary glucuronidation targets. The ferric iron reducing ability of the glucuronidated reaction mixture was reduced, while the free radical scavenging abilities of mangiferin, utilising on-line post-column HPLC-DAD-DPPH· and HPLC-DAD-ABTS·+ assays, were eliminated, providing further evidence that the catechol arrangement at C-6 and C-7 was the preferred site of conjugation. This paper provides the first evidence that the glucuronidated metabolites of mangiferin resulted in a loss in free radical scavenging and ferric iron reducing ability. PMID:22137905

van der Merwe, J Debora; Joubert, Elizabeth; Manley, Marena; de Beer, Dalene; Malherbe, Christiaan J; Gelderblom, Wentzel C A

2012-03-01

44

Hepatocyte cotransport of taurocholate and bilirubin glucuronides: Role of microtubules  

SciTech Connect

Modulation of bile pigment excretion by bile salts has been attributed to modification of canalicular membrane transport or a physical interaction in bile. Based on the observation that a microtubule-dependent pathway is involved in the hepatocellular transport of bile salts, the authors investigated the possibility that bilirubin glucuronides are associated with bile salts during intracellular transport. Experiments were conducted in intact rats (basal) or after overnight biliary diversion and intravenous reinfusion of taurocholate (depleted/reinfused). All rats were pretreated with intravenous low-dose colchicine or its inactive isomer lumicolchicine. Biliary excretion of radiolabeled bilirubin glucuronides derived from tracer ({sup 14}C)bilirubin-({sup 3}H)bilirubin monoglucuronide (coinjected iv) was unchanged in basal rats but was consistently delayed in depleted/reinfused rats. This was accompanied by a significant shift toward bilirubin diglucuronide formation from both substrates. In basal Gunn rats, with deficient bilirubin glucuronidation, biliary excretion of intravenous ({sup 14}C)bilirubin monoglucuronide-({sup 3}H)bilirubin diglucuronide was unaffected by colchicine but was retarded in depleted/reinfused Gunn rats. Colchicine had no effect on the rate of bilirubin glucuronidation in vitro in rat liver microsomes. They conclude that a portion of the bilirubin glucuronides generated endogenously in hepatocytes or taken up directly from plasma may be cotransported with bile salts to the bile canalicular membrane via a microtubule-dependent mechanism.

Crawford, J.M.; Gollan, J.L. (Harvard Medical School, Boston, MA (USA))

1988-07-01

45

Assessment of nalmefene glucuronide as a selective gut opioid antagonist.  

PubMed

Opioid use often causes troublesome constipation as a side-effect. Selective antagonism of the intestinal actions of opioids might be useful in the treatment of opioid-induced constipation. We tested the inactive metabolite of nalmefene, nalmefene glucuronide, which showed promise of gut selectivity in rodent models, by administering ascending doses in single-blind, placebo-controlled fashion to five methadone-maintained, opioid-dependent male volunteers. Assessment of whether systemic or gut-selective opioid antagonist effects occurred was measured by vital signs, pupillary diameter, opioid withdrawal symptom scales, and bowel function. Oral nalmefene glucuronide precipitated symptoms and signs consistent with the opioid abstinence syndrome in all five subjects a mean of 9.0 h after dosing. We conclude that nalmefene glucuronide does not appear to exert sufficient gut selectivity to be useful in antagonizing constipation due to exogenous opioid administration without antagonizing systemic opioid effects. PMID:8529534

Cheskin, L J; Chami, T N; Johnson, R E; Jaffe, J H

1995-08-01

46

Enzyme-assisted synthesis and characterization of glucuronide conjugates of neuroactive steroids.  

PubMed

Synthesis of reference standards is needed to determine the presence and function of steroid glucuronides in the brain or other tissues, because commercial sources of steroid glucuronide standards are limited or unavailable. In the present study porcine, rat, and bovine liver microsomes were tested to evaluate their ability to glucuronidate eight neurosteroids and neuroactive steroids of various types: dehydroepiandrosterone, pregnenolone, isopregnanolone, 5alpha-tetrahydrodeoxycorticosterone, corticosterone, cortisol, beta-estradiol, and testosterone. In general, the glucuronidation efficiency of rat liver was rather poor compared with that of bovine and porcine liver microsomes. Since porcine liver apparently has a relatively large amount of dehydrogenase, its microsomes also produced dehydrogenated steroids and their glucuronides, as well as various regioisomers in which the site of glucuronidation varied. In contrast, bovine liver microsomes produced mainly a single major glucuronidation product and few dehydrogenation products and gave the best overall yield for two-third of the steroids tested. The enzymatic synthesis of five glucuronides of four steroids was carried out and the conditions, purification, and analytical methods for the glucuronidation products were optimized. The steroid glucuronides synthesized were characterized by nuclear magnetic resonance spectroscopy (NMR) and liquid chromatography-mass spectrometry (LC-MS). The stereochemically pure steroid glucuronide conjugates were recovered in milligram amounts (yield 10-78%) and good purity (>85-90%), which is sufficient for LC-MS/MS method development and analyses of steroid glucuronides in biological matrices such as brain, urine, or plasma. PMID:17250861

Jäntti, Sirkku E; Kiriazis, Alexandros; Reinilä, Ruut R; Kostiainen, Risto K; Ketola, Raimo A

2007-03-01

47

Resveratrol Is Absorbed in the Small Intestine as Resveratrol Glucuronide  

Microsoft Academic Search

We have studied the absorption and metabolism of resveratrol in the jejunum in an isolated rat small intestine model. Only small amounts of resveratrol were absorbed across the enterocytes of the jejunum and ileum unmetabolised. The major compound detected on the serosal side was the glucuronide conjugate of resveratrol (96.5% ± 4.6 of the amount absorbed) indicating the susceptibility of

Gunter Kuhnle; Jeremy P. E. Spencer; George Chowrimootoo; Hagen Schroeter; Edward S. Debnam; S. Kaila S. Srai; Catherine Rice-Evans; Ulrich Hahn

2000-01-01

48

Morphine glucuronidation in human fetal and adult liver  

Microsoft Academic Search

Summary  The glucuronyltransferase activity towards morphine was measured in microsomes isolated from liver specimens obtained from\\u000a human fetuses and cancer patients. All the fetal livers investigated had measurable UDP-glucuronyltransferase activity towards\\u000a morphine. There was no correlation between the gestational age (15 to 27 weeks) and the glucuronidation rate. The mean value\\u000a of the enzymatic activities was higher in fetal livers obtained

G. M. Pacifici; J. Säwe; L. Kager; A. Rane

1982-01-01

49

Ethyl Alcohol Production.  

E-print Network

and Natural Resources Advisory Council. Ethyl Alcohol Production Henry O'Neal* rEXAS MM UNiVERSITY UBRAR't The Agricultural Engineering Department at Texas A&M University has been operating a research and demonstration ethyl alcohol production plant... since January 1981 as part of an alternate energy program. The plant is located on the Texas A&M University West Campus at the Agricultural Engineering Research Shop and is representative of a small, farm scale facility. Alcohol Production Steps...

O'Neal, Henry

1981-01-01

50

The effect of valproic acid on drug and steroid glucuronidation by expressed human UDP-glucuronosyltransferases  

Microsoft Academic Search

Valproic acid glucuronidation kinetics were carried out with three human UGT isoforms: UGT1A6, UGT1A9, and UGT2B7 as well as human liver and kidney microsomes. The glucuronidation of valproic acid was typified by high Km values with microsomes and expressed UGTs (2.3–5.2mM). The ability of valproic acid to interact with the glucuronidation of drugs, steroids and xenobiotics in vitro was investigated

Brian T Ethell; Gail D Anderson; Brian Burchell

2003-01-01

51

Glucuronidation of Psilocin and 4-Hydroxyindole by the Human UDP-Glucuronosyltransferases  

PubMed Central

We have examined the glucuronidation of psilocin, a hallucinogenic indole alkaloid, by the 19 recombinant human UDP-glucuronosyltransferases (UGTs) of subfamilies 1A, 2A, and 2B. The glucuronidation of 4-hydroxyindole, a related indole that lacks the N,N-dimethylaminoethyl side chain, was studied as well. UGT1A10 exhibited the highest psilocin glucuronidation activity, whereas the activities of UGTs 1A9, 1A8, 1A7, and 1A6 were significantly lower. On the other hand, UGT1A6 was by far the most active enzyme mediating 4-hydroxyindole glucuronidation, whereas the activities of UGTs 1A7–1A10 toward 4-hydroxyindole resembled their respective psilocin glucuronidation rates. Psilocin glucuronidation by UGT1A10 followed Michaelis-Menten kinetics in which psilocin is a low-affinity high-turnover substrate (Km = 3.8 mM; Vmax = 2.5 nmol/min/mg). The kinetics of psilocin glucuronidation by UGT1A9 was more complex and may be best described by biphasic kinetics with both intermediate (Km1 = 1.0 mM) and very low affinity components. The glucuronidation of 4-hydroxyindole by UGT1A6 exhibited higher affinity (Km = 178 ?M) and strong substrate inhibition. Experiments with human liver and intestinal microsomes (HLM and HIM, respectively) revealed similar psilocin glucuronidation activity in both samples, but a much higher 4-hydroxyindole glucuronidation rate was found in HLM versus HIM. The expression levels of UGTs 1A6–1A10 in different tissues were studied by quantitative real-time-PCR, and the results, together with the activity assays findings, suggest that whereas psilocin may be subjected to extensive glucuronidation by UGT1A10 in the small intestine, UGT1A9 is likely the main contributor to its glucuronidation once it has been absorbed into the circulation. PMID:20007669

Manevski, Nenad; Kurkela, Mika; Hoglund, Camilla; Mauriala, Timo; Court, Michael H.; Yli-Kauhaluoma, Jari

2010-01-01

52

N+-glucuronidation, a common pathway in human metabolism of drugs with a tertiary amine group.  

PubMed

Glucuronidation of either an aliphatic or aromatic tertiary amine group in a molecule results in a quaternary ammonium-linked glucuronide metabolite (i.e. N+-glucuronide). The development of sound information on N+-glucuronide metabolites, including their characterization, has been slow. In part, this is because the presence of both the carboxylic acid group and cationic center in their structure imparts physiochemical properties such that procedures used in their analysis, including extraction, require judicious selection. The techniques used in the identification of N+-glucuronide metabolites and those metabolites identified in human urine are the focus of this review. Especially useful in their identification are the availability of an authentic synthetic sample and the use of mass spectrometry and nuclear magnetic resonance (NMR) techniques that, in the first instance, involve atmospheric pressure ionization or fast atom bombardment modes of ionization and high-resolution 1H NMR. More than 30 N+-glucuronide metabolites of xenobiotics have been identified in human urine. In particular, N+-glucuronidation is a common phenomenon in the metabolism of H1 antihistamine and antidepressant drugs with an aliphatic tertiary amine group. Those marketed drugs in which the reported N+-glucuronide mean urinary excretion of the orally administered dose exceeds 10% include cyclizine, cyclobenzaprine, cyproheptadine, dothiepin, doxepin, ketotifen, lamotrigine, mianserin, and tioconazole. The pharmacological importance of N+-glucuronidation has not been clarified. PMID:9733660

Hawes, E M

1998-09-01

53

Isolation and identification of seven glucuronide conjugates of andrographolide in human urine.  

PubMed

Andrographolide is one of the principal components of a famous traditional Chinese herbal medicine, Andrographis paniculate (Burm) Nees, and has been widely used in the clinic for the treatment of infectious diseases. In this paper, metabolites of andrographolide in the urine of eight healthy volunteers after oral administration were further investigated. Building on previous findings, an additional seven phase II metabolites were isolated by liquid-liquid extraction, open-column chromatography, medium-pressure liquid chromatography, and, finally, preparative high-performance liquid chromatography. Structural elucidation was carried out by mass spectra and NMR spectroscopy including 1H NMR, 13C NMR and two-dimensional NMR (distortionless enhancement by polarization transfer, heteronuclear multiple-quantum correlation, heteronuclear multiple-bond correlation, 1H-1H correlated spectroscopy, and nuclear Overhauser enhancement spectroscopy). All of the metabolites were characterized as glucuronide conjugates, and the structures were determined to be andrographolide-19-O-beta-D-glucuronide (M-1), isoandrographolide-19-O-beta-D-glucuronide (M-2), 14-deoxy-12-hydroxy-andrographolide-19-O-beta-D-glucuronide (M-3), andrographolide-19-O-[6'-methyl-beta-D-glucuronide] (M-4), 14-deoxy-12(13)-en-andrographolide-19-O-beta-D-glucuronide (M-5), 14-deoxyandrographolide-19-O-beta-D-glucuronide (M-6), and 3-oxoandrographolide-19-O-beta-D-glucuronide (M-7), respectively. PMID:15644451

Cui, Liang; Qiu, Feng; Yao, Xinsheng

2005-04-01

54

UDP-glucuronosyltransferases 1A6 and 1A10 catalyze reduced menadione glucuronidation  

SciTech Connect

Menadione (2-methyl-1,4-naphthoquine), also known as vitamin K3, has been widely used as a model compound in the field of oxidative stress-related research. The metabolism of menadione has been studied, and it is known that menadione undergoes a two-electron reduction by NAD(P)H:Quinone oxidoreductase 1 (NQO1) after which the reduced form of menadione (2-methyl-1,4-naphthalenediol, menadiol) is glucuronidated and excreted in urine. To investigate which human UDP-glucuronosyltransferase (UGT) isoforms participate in the glucuronidation of menadiol reduced by NQO1 from menadione, we first constructed heterologously expressed NQO1 in Sf9 cells and tested the menadiol glucuronidating activity of 16 human recombinant UGT isoforms. Of the 16 UGT isoforms, UGTs 1A6, 1A7, 1A8, 1A9, and 1A10 catalyzed menadiol glucuronidation, and, of these, UGTs 1A6 and 1A10 catalyzed menadiol glucuronidation at much higher rates than the other UGTs. Menadiol was regioselectively glucuronidated in the manner of 4-position > 1-position by UGTs 1A7, 1A8, 1A9, and 1A10. In contrast to these UGTs, only UGT1A6 exhibited 1-menadiol-preferential glucuronidating activity. The results suggest possible detoxification pathways for quinones via NQO1 reduction followed by UGT glucuronidation.

Nishiyama, Takahito; Ohnuma, Tomokazu; Inoue, Yuu; Kishi, Takehiko; Ogura, Kenichiro [Department of Drug Metabolism and Molecular Toxicology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji-shi, Tokyo 192-0392 (Japan); Hiratsuka, Akira [Department of Drug Metabolism and Molecular Toxicology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji-shi, Tokyo 192-0392 (Japan)], E-mail: hiratuka@ps.toyaku.ac.jp

2008-06-27

55

Hesperetin glucuronides induce adipocyte differentiation via activation and expression of peroxisome proliferator-activated receptor-?.  

PubMed

In previous reports, hesperidin, a flavonoid glucoside from citrus fruit, is hydrolyzed to hesperetin, an aglycone of hesperidin, and converted to the hesperetin glucuronides (H7-OG and H3'-OG) in vivo and depresses blood glucose levels. But there are no reports on the activity of hesperetin glucuronides. To determine the activity of hesperetin glucuronides, H7-OG and H3'-OG were synthesized and peroxisome proliferator-activated receptor-? (PPAR?) agonist activity was observed at 250 ?M. These glucuronides accelerated the differentiation of 3T3-L1 cells into adipocytes at 10 ?M. Furthermore, H7-OG showed additive effects in reporter gene assays and caused noncompetitive reactions in time-resolved fluorescence resonance energy transfer assays with a thiazolidinedione derivative. Our results indicated that hesperetin glucuronides activated PPAR?, accelerated adipocyte differentiation. PMID:25036134

Gamo, Kanae; Miyachi, Hiroyuki; Nakamura, Kayoko; Matsuura, Nobuyasu

2014-01-01

56

Glucuronidation of resveratrol, a natural product present in grape and wine, in the human liver.  

PubMed

1. Resveratrol, a polyphenolic compound present in grape and wine, has beneficial effects against cancer and protective effects on the cardiovascular system. It has been shown that the compound is sulphated in human liver and the aims of the present investigation were to study resveratrol glucuronidation in human liver microsomes and to determine whether flavonoids inhibit resveratrol glucuronidation. 2. A simple and reproducible radiometric assay for resveratrol glucuronidation was developed. The assay employed uridine-5'-diphosphoglucuronic acid-[14C] and unlabelled resveratrol. Resveratrol-glucuronide was isolated by TLC. The intra- and interassays variabilities were 1 and 1.5%, respectively. 3. The rate of resveratrol glucuronidation was measured in 10 liver samples. The mean +/- SD and median of resveratrol glucuronidation rate were 0.69 +/- 0.34 and 0.80 nmol/min/mg, respectively. Resveratrol glucuronosyl transferase followed Michaelis-Menten kinetics and the Km and Vmax (mean +/- SD; n = 5) were 0.15 +/- 0.09 mM and 1.3 +/- 0.3 nmol/min/mg, respectively. The intrinsic clearance was 11 +/- 4 x 10(-3) ml/min.mg. 4. The flavonoid quercetin inhibited resveratrol glucuronidation and its IC50 (mean +/- SD; n = 3) was 10 +/- 1 microM. Myricetin, catechin, kaempferol, fisetin and apigenin (all at 20 microM) inhibited resveratrol glucuronidation and the percent of control ranged between 46% (catechin) to 72% (apigenin). 5. The present results show that resveratrol is glucuronated in the human liver. Glucuronidation may reduce the bioavailability of this compound however, flavonoids inhibit resveratrol glucuronidation and such an inhibition might improve the bioavailability of resveratrol. PMID:11197066

de Santi, C; Pietrabissa, A; Mosca, F; Pacifici, G M

2000-11-01

57

Steviol glucuronidation and its potential interaction with UDP-glucuronosyltransferase 2B7 substrates.  

PubMed

Hydrolysis of stevioside and rebaudioside A in the gastrointestinal tract after oral intake leads to the formation of steviol, the aglycone, which is absorbed into the circulation. Although in vivo studies have shown that steviol is cleared from the body via glucuronidation, the role of liver vs. intestine in steviol glucuronidation has not been well defined and related UDP-glucuronosyltransferases (UGTs) have not been identified. The present study investigated steviol glucuronidation and obtained kinetic parameters in liver and intestinal microsomes of human and rat, as well as in recombinant human UGT systems. Results suggest that organ specificity exists in the intrinsic clearance of the glucuronidation reaction. Steviol glucuronidation was primarily mediated by UGT2B7 at low concentration and UGT2B7 and UGT1A3 at high concentration. Inhibition studies with selected UGT2B7 substrates indicate that diclofenac displayed a relatively strong inhibition (Ki, 4.2 ?M) against steviol glucuronidation in human liver microsomes. Taken together, the identification of the involvement of UGT2B7 in steviol glucuronidation would provide a mechanistic basis for the evaluation of the interaction between steviol and diclofenac. As metabolic clearance of botanical-derived products can be the objects (victims) of botanical-drug interactions, further studies are needed to investigate the in vivo relevance of such interactions. PMID:24296138

Wang, Meiyu; Lu, Jia; Li, Jiajun; Qi, Huixin; Wang, Yedong; Zhang, Hongjian

2014-02-01

58

Ion-pair high-performance liquid chromatographic separation of two thyroxine glucuronides formed by rat liver microsomes.  

PubMed

A simple reversed-phase ion-pair high-performance liquid chromatographic separation method has been developed for thyroxine (T4) and its glucuronide metabolites formed by liver microsomes of untreated and 3-methylcholanthrene-treated rats. Besides the phenol-T4-glucuronide, another, probably acyl-T4-glucuronide, formation has been detected. The effect of pH and temperature on the stability of the acyl-T4-glucuronide was also investigated. The lowering of pH to 2 and cooling the samples to 5 degrees C is necessary to prevent the hydrolysis of acylglucuronide, while both pH and temperature do not affect the stability of the phenol-T4-glucuronide. The retention times of T4 and phenol-T4-glucuronide are highly influenced by the pH of the mobile phase, but not that of acyl-T4-glucuronide. PMID:8811451

Jemnitz, K; Vereczkey, L

1996-06-01

59

Variation in Trans-3?-Hydroxycotinine Glucuronidation Does Not Alter the Nicotine Metabolite Ratio or Nicotine Intake  

PubMed Central

Background CYP2A6 metabolizes nicotine to its primary metabolite cotinine and also mediates the metabolism of cotinine to trans-3?-hydroxycotinine (3HC). The ratio of 3HC to cotinine (the “nicotine metabolite ratio”, NMR) is an in vivo marker for the rate of CYP2A6 mediated nicotine metabolism, and total nicotine clearance, and has been associated with differences in numerous smoking behaviors. The clearance of 3HC, which affects the NMR, occurs via renal excretion and metabolism by UGT2B17, and possibly UGT2B10, to 3HC-glucuronide. We investigated whether slower 3HC glucuronidation alters NMR, altering its ability to predict CYP2A6 activity and reducing its clinical utility. Methods Plasma NMR, three urinary NMRs, three urinary 3HC glucuronidation phenotypes and total nicotine equivalents were examined in 540 African American smokers. The UGT2B17 gene deletion and UGT2B10*2 were genotyped. Results The UGT2B17 gene deletion, but not UGT2B10*2 genotype, was associated with slower 3HC glucuronidation (indicated by three 3HC-glucuronidation phenotypes), indicating its role in this glucuronidation pathway. However, neither lower rates of 3HC glucuronidation, nor the presence of a UGT2B17 and UGT2B10 reduced function allele, altered plasma or urinary NMRs or levels of smoking. Conclusions Variation in 3HC glucuronidation activity, including these caused by UGT2B17 gene deletions, did not significantly alter NMR and is therefore unlikely to affect the clinical utility of NMR in smoking behavior and cessation studies. This study demonstrates that NMR is not altered by differences in the rate of 3HC glucuronidation, providing further support that NMR is a reliable indicator of CYP2A6 mediated nicotine metabolism. PMID:23936477

Zhu, Andy Z. X.; Zhou, Qian; Cox, Lisa Sanderson; Ahluwalia, Jasjit S.; Benowitz, Neal L.; Tyndale, Rachel F.

2013-01-01

60

Improved detection of opioid use in chronic pain patients through monitoring of opioid glucuronides in urine.  

PubMed

When chronic pain patients are suspected of being non-compliant, their therapy can be withdrawn. Therefore, sensitive and specific confirmatory testing is important for identifying diversion and adherence. This work aimed to develop a novel liquid chromatography tandem mass spectrometry (LC-MS-MS) method to detect 14 opioids and six opioid glucuronide metabolites in urine with minimal sample preparation. Analytes included were morphine, oxymorphone, hydromorphone, oxycodone, hydrocodone, codeine, fentanyl, norfentanyl, 6-monoacetylmorphine, meperidine, normeperidine, propoxyphene, methadone, buprenorphine, morphine-3-glucuronide, morphine-6-glucuronide, oxymorphone glucuronide, hydromorphone glucuronide, codeine-6-glucuronide and norbuprenorphine glucuronide. Samples were processed by centrifugation and diluted in equal volume with a deuterated internal standard containing 14 opioids and four opioid glucuronides. The separation of all compounds was complete in nine minutes. The assay was linear between 10 and 1,000 ng/mL (fentanyl 0.25-25 ng/mL). Intra-assay imprecision (500 ng/mL, fentanyl 12.5 ng/mL) ranged from 1.0 to 8.4% coefficient of variation. Inter-assay precision ranged from 2.9 to 6.0%. Recovery was determined by spiking five patient specimens with opioid and opioid glucuronide standards at 100 ng/mL (fentanyl 2.5 ng/mL). Recoveries ranged from 82 to 107% (median 98.9%). The method correlated with our current quantitative LC-MS-MS assay for opioids, which employs different chromatography. Internal standards were not available for every analyte to critically evaluate for ion suppression. Instead, a novel approach was designed to achieve the most rigorous quality control possible, in which the recovery of each analyte was evaluated in each negative sample. PMID:22833646

Dickerson, Jane A; Laha, Thomas J; Pagano, Monica B; O'Donnell, Brendan R; Hoofnagle, Andrew N

2012-10-01

61

In Vitro Stability of Free and Glucuronidated Cannabinoids in Blood and Plasma Following Controlled Smoked Cannabis  

PubMed Central

BACKGROUND Blood and plasma cannabinoid stability is important for test interpretation and is best studied in authentic rather than fortified samples. METHODS Low and high blood and plasma pools were created for each of 10 participants after they smoked a cannabis cigarette. The stabilities of ?9-tetrahydrocannabinol (THC), 11-hydroxy-THC (11-OH-THC), 11-nor-9-carboxy-THC (THCCOOH), cannabidiol (CBD), cannabinol (CBN), THC-glucuronide, and THCCOOH-glucuronide were determined after 1 week at room temperature; 1, 2, 4, 12, and 26 (±2) weeks at 4 °C; and 1, 2, 4, 12, 26 (±2), and 52 (±4) weeks at ?20 °C. Stability was assessed by Friedman test. RESULTS Numbers of THC-glucuronide and CBD-positive blood samples were insufficient to assess stability. In blood, 11-OH-THC and CBN were stable for 1 week at room temperature, whereas THC and THCCOOH-glucuronide decreased and THCCOOH increased. In blood, THC, THCCOOH-glucuronide, THCCOOH, 11-OH-THC, and CBN were stable for 12, 4, 4, 12, and 26 weeks, respectively, at 4 °C and 12, 12, 26, 26, and 52 weeks at ?20 °C. In plasma, THC-glucuronide, THC, CBN, and CBD were stable for 1 week at room temperature, whereas THCCOOH-glucuronide and 11-OH-THC decreased and THCCOOH increased. In plasma, THC-glucuronide, THC, THCCOOH-glucuronide, THCCOOH, 11-OH-THC, CBN, and CBD were stable for 26, 26, 2, 2, 26, 12, and 26 weeks, respectively, at 4 °C and 52, 52, 26, 26, 52, 52, and 52 weeks, respectively, at ?20 °C. CONCLUSIONS Blood and plasma samples should be stored at ?20 °C for no more than 3 and 6 months, respectively, to assure accurate cannabinoid quantitative results. PMID:23519966

Karschner, Erin L.; Desrosiers, Nathalie A.; Gorelick, David A.; Huestis, Marilyn A.

2013-01-01

62

Dietary green and white teas suppress UDP-glucuronosyltransferase UGT2B17 mediated testosterone glucuronidation.  

PubMed

The anabolic steroid testosterone can be used by athletes to enhance athletic performance and muscle growth. UDP-glucuronosyltransferase (UGT2B17) is the key enzyme involved in the glucuronidation of testosterone to testosterone glucuronide, which also serves as a marker for the testosterone/epitestosterone (T/E) ratio used to detect testosterone abuse in sport. Inhibitors of testosterone glucuronidation could have an impact on circulating testosterone levels, thus aiding performance, as well as potentially affecting the urinary T/E ratio and therefore masking testosterone abuse. Previous reports have revealed that non-steroidal, anti-inflammatory drugs, diclofenac and ibuprofen, inhibit the UGT2B17 enzyme. The aim of this study is to analyse dietary tea samples for inhibition of testosterone glucuronidation and, where inhibition is present, to identify the active compounds. Analysis of testosterone glucuronidation was conducted by performing UGT2B17 assays with detection of un-glucuronidated testosterone using high performance liquid chromatography. The results from this study showed that testosterone glucuronidation was inhibited by the green and white tea extracts, along with specific catechin compounds, notably: epicatechin, epigallocatechin gallate (EGCG) and catechin gallate. The IC50 inhibition value for EGCG was determined, using a Dixon plot, to be 64 ?M, equalling the most active NSAID inhibitor diclofenac. Thus, common foodstuffs and their constituents, for the first time, have been identified as inhibitors of a key enzyme involved in testosterone glucuronidation. Whilst these common compounds are not substrates of the UGT2B17 enzyme, we showed that they inhibit testosterone glucuronidation which may have implications on current doping control in sport. PMID:22429924

Jenkinson, Carl; Petroczi, Andrea; Barker, James; Naughton, Declan P

2012-05-01

63

Glucuronidation of bile acids under flow conditions: design of experiments and Koenigs-Knorr reaction optimization.  

PubMed

An efficient method for the C3-glucuronidation of bile acids is developed under flow conditions. A modular mesoreactor assisted flow set-up was combined with statistical design of experiments to speed up the optimization of the Koenigs-Knorr reaction in terms of yield, regioselectivity, costs, as well as technical and practical standpoints. Using the optimal conditions, selective glucuronidation of naturally occurring bile acids was successfully achieved offering a new, valuable route to C3-glucuronidated bile acids useful for biological, diagnostic and PK/ADMET investigations. PMID:25338931

Mostarda, Serena; Filipponi, Paolo; Sardella, Roccaldo; Venturoni, Francesco; Natalini, Benedetto; Pellicciari, Roberto; Gioiello, Antimo

2014-12-21

64

Ethyl fuel from nonpetroleum sources  

Microsoft Academic Search

It has been shown that ethanol-ester mixtures - Ethyl Fuel - can be prepared from nonpetroleum sources such as coal, oil shale, etc. Production consists of the following steps: gasification of basic feedstock, synthesis of methanol and carbonylation of methanol to Ethyl Fuel. Depending on the final composition, preparation from methanol can be carried out with 92 + % selectivity.

H. Beuther; T. P. Kobylinski; G. M. Singerman; W. R. Pretzer

1980-01-01

65

Glucuronidation and Sulfation Kinetics of Diflunisal in Man.  

NASA Astrophysics Data System (ADS)

Diflunisal is a nonsteroidal anti-inflammatory drug used in the treatment of arthritis and musculoskeletal pain. Diflunisal exhibits concentration- and dose-dependent kinetics, the mechanism of which has not been determined. The purpose of this study was to determine the mechanism(s) responsible for non-linear disposition of diflunisal and to examine environmental factors which may affect the elimination of diflunisal. The metabolites of diflunisal, including a new metabolite, the sulphate conjugate, were purified by column and semi-preparative high pressure liquid chromatography. Assays for the quantitation of diflunisal and conjugates in urine and diflunisal in plasma were developed. Plasma protein binding of diflunisal in blank plasma and in plasma obtained following multiple doses of diflunisal was determined by equilibrium dialysis. Total body clearance of diflunisal decreased when dose increased from 100 to 750 mg. Total clearance increased when dose increased from 750 to 1000 mg. The percent of recovered dose eliminated as the acyl glucuronide decreased and the percent eliminated as the sulphate increased with increasing dose of diflunisal. Plasma protein binding of diflunisal was concentration dependent over a range of diflunisal plasma concentrations of 3 to 257 mug/ml. Total clearance, and to a lesser degree, unbound clearance of diflunisal were decreased following multiple dose administration of 250 and 500 mg diflunisal. Percent of recovered dose eliminated as the acyl glucuronide decreased and percent eliminated as the sulphate conjugate increased following multiple dosing. Plasma protein binding of diflunisal was similar in blank plasma and plasma obtained at steady state. Unbound clearance of diflunisal exceeded liver plasma flow. Frequency distributions of the elimination of the conjugates of diflunisal were normally distributed. Sex, smoking, and use of vitamins or oral contraceptives were identified as factors which may affect the elimination of diflunisal.

Loewen, Gordon Rapheal

66

DEVELOPMENT OF A CLASS-SELECTIVE ENZYME IMMUNOASSAY FOR URINARY PHENOLIC GLUCURONIDES. (R825433)  

EPA Science Inventory

Class-selective immunoassays for the measurement of glucuronides in human urine can aid evaluation of human exposure to complex mixtures of xenobiotics. Therefore, an enzyme immunoassay (EIA) for the group-selective detection of phenolic ...

67

In vitro glucuronidation of the antibacterial triclocarban and its oxidative metabolites.  

PubMed

Triclocarban (3,4,4'-trichlorocarbanilide; TCC) is widely used as an antibacterial in bar soaps. During use of these soaps, a significant portion of TCC is absorbed by humans. For the elimination from the body, glucuronidation plays a key role in both biliary and renal clearance. To investigate this metabolic pathway, we performed microsomal incubations of TCC and its hydroxylated metabolites 2'-OH-TCC, 3'-OH-TCC, and 6-OH-TCC. Using a new liquid chromatography-UV-mass spectrometry method, we could show a rapid glucuronidation for all OH-TCCs by the uridine-5'-diphosphate-glucuronosyltransferases (UGT) present in liver microsomes of humans (HLM), cynomolgus monkeys (CLM), rats (RLM), and mice (MLM). Among the tested human UGT isoforms, UGT1A7, UGT1A8, and UGT1A9 showed the highest activity for the conjugation of hydroxylated TCC metabolites followed by UGT1A1, UGT1A3, and UGT1A10. Due to this broad pattern of active UGTs, OH-TCCs can be efficiently glucuronidated in various tissues, as shown for microsomes from human kidney (HKM) and intestine (HIM). The major renal metabolites in humans, TCC-N-glucuronide and TCC-N'-glucuronide, were formed at very low conversion rates (<1%) by microsomal incubations. Low amounts of N-glucuronides were generated by HLM, HIM, and HKM, as well as by MLM and CLM, but not by RLM, according to the observed species specificity of this metabolic pathway. Among the human UGT isoforms, only UGT1A9 had activity for the N-glucuronidation of TCC. These results present an anomaly where in vivo the predominant urinary metabolites of TCC are N and N'-glucuronides, but these compounds are slowly produced in vitro. PMID:21953915

Schebb, N H; Franze, B; Maul, R; Ranganathan, A; Hammock, B D

2012-01-01

68

In Vitro Glucuronidation of the Antibacterial Triclocarban and Its Oxidative MetabolitesS?  

PubMed Central

Triclocarban (3,4,4?-trichlorocarbanilide; TCC) is widely used as an antibacterial in bar soaps. During use of these soaps, a significant portion of TCC is absorbed by humans. For the elimination from the body, glucuronidation plays a key role in both biliary and renal clearance. To investigate this metabolic pathway, we performed microsomal incubations of TCC and its hydroxylated metabolites 2?-OH-TCC, 3?-OH-TCC, and 6-OH-TCC. Using a new liquid chromatography-UV-mass spectrometry method, we could show a rapid glucuronidation for all OH-TCCs by the uridine-5?-diphosphate-glucuronosyltransferases (UGT) present in liver microsomes of humans (HLM), cynomolgus monkeys (CLM), rats (RLM), and mice (MLM). Among the tested human UGT isoforms, UGT1A7, UGT1A8, and UGT1A9 showed the highest activity for the conjugation of hydroxylated TCC metabolites followed by UGT1A1, UGT1A3, and UGT1A10. Due to this broad pattern of active UGTs, OH-TCCs can be efficiently glucuronidated in various tissues, as shown for microsomes from human kidney (HKM) and intestine (HIM). The major renal metabolites in humans, TCC-N-glucuronide and TCC-N?-glucuronide, were formed at very low conversion rates (<1%) by microsomal incubations. Low amounts of N-glucuronides were generated by HLM, HIM, and HKM, as well as by MLM and CLM, but not by RLM, according to the observed species specificity of this metabolic pathway. Among the human UGT isoforms, only UGT1A9 had activity for the N-glucuronidation of TCC. These results present an anomaly where in vivo the predominant urinary metabolites of TCC are N and N?-glucuronides, but these compounds are slowly produced in vitro. PMID:21953915

Schebb, N. H.; Franze, B.; Maul, R.; Ranganathan, A.

2012-01-01

69

Profiling of 19-norandrosterone sulfate and glucuronide in human urine: Implications in athlete's drug testing  

Microsoft Academic Search

19-Norandrosterone (19-NA) as its glucuronide derivative is the target metabolite in anti-doping testing to reveal an abuse of nandrolone or nandrolone prohormone. To provide further evidence of a doping with these steroids, the sulfoconjugate form of 19-norandrosterone in human urine might be monitored as well. In the present study, the profiling of sulfate and glucuronide derivatives of 19-norandrosterone together with

Emmanuel Strahm; Norbert Baume; Patrice Mangin; Martial Saugy; Christiane Ayotte; Christophe Saudan

2009-01-01

70

Sex-specific differences in levels of morphine, morphine-3-glucuronide, and morphine antinociception in rats  

Microsoft Academic Search

A number of studies reported striking differences in antinociceptive responses to morphine as a function of sex. Although sex differences in the sensitivity to morphine are widely characterized in rodents, the underlying causes are not identified. Gonadal steroids are believed to contribute to sex differences in response to opioid-induced antinociception. In rats, morphine is metabolized by glucuronidation to morphine-3-glucuronide (M3G).

Lanning Baker; Anna Ratka

2002-01-01

71

A concise synthesis of glucuronide metabolites of urolithin-B, resveratrol, and hydroxytyrosol  

Microsoft Academic Search

A simple and direct strategy to chemically synthesize O-?-d-glucuronides of urolithin-B 4, resveratrol 5, and the corresponding hydroxytyrosol derivatives 6, 7 (as a regioisomeric mixture), and 8 is described. The critical glycosylation step has been optimized using a structurally simple phenol, urolithin-B, by modification of several reaction parameters (solvent, promoter, and glucuronide donor). Very high yields have been obtained in

Ricardo Lucas; David Alcantara; Juan Carlos Morales

2009-01-01

72

High-performance liquid chromatographic assay for acetaminophen glucuronide in human liver microsomes  

Microsoft Academic Search

A rapid and specific high-performance liquid chromatographic assay was developed for the determination of acetaminophen glucuronide formed by human liver microsomes. In addition, incubation conditions were systematically evaluated. Conditions that yielded the optimal rate of acetaminophen glucuronide formation over various concentrations of acetaminophen (0.15–30 mM) consisted of the following: 0.1 M potassium phosphate buffer, 1 mM magnesium chloride, 30 ?g\\/mg

Khalid M. Alkharfy; Reginald F. Frye

2001-01-01

73

Effect of valerian, valerian/hops extracts, and valerenic acid on glucuronidation in vitro.  

PubMed

Valerian preparations alone or in combination with hops are popular over-the-counter products used for sleep disturbances or anxiety. Therefore, it is important to characterize the effect of these products on the activity of human drug-metabolizing enzymes. The inhibitory effects of valerian and valerian/hops extracts as well as valerenic acid (a major constituent of valerian) on glucuronidation were evaluated in human liver microsomes and with expressed uridine 5'-diphosphate (UDP)-glucuronosyltransferases (UGT). Methanolic extracts of two herbal preparations caused significant reductions in the rate of formation of acetaminophen, oestradiol, morphine, and testosterone glucuronides. Oestradiol glucuronidation at the 3-hydroxy position was inhibited by nearly 87% in microsomal incubations. In addition, marked reductions in UGT1A1 and UGT2B7 activities were observed in the presence of the herbal extracts using oestradiol and morphine as probe substrates, respectively. Valerenic acid also demonstrated significant inhibitory effects on the glucuronidation of acetaminophen, oestradiol, and morphine with both microsomes and expressed UGTs. The relatively low IC50 values obtained for valerenic acid in microsomal incubations may indicate that this essential oil contributes to the effects observed with herbal extracts in inhibiting glucuronidation in vitro. Overall, these findings suggest that valerian-containing products may interfere with the glucuronidation of endo- and xenobiotics. PMID:17484515

Alkharfy, K M; Frye, R F

2007-02-01

74

Method for quantification of morphine and its 3- and 6-glucuronides, codeine, codeine glucuronide and 6-monoacetylmorphine in human blood by liquid chromatography–electrospray mass spectrometry for routine analysis in forensic toxicology  

Microsoft Academic Search

Simultaneous determination of opiates and their glucuronides in body fluids has a great practical interest in the forensic assessment of heroin intoxication. A selective and sensitive method for quantification of morphine and its 3- and 6-glucuronides, codeine, codeine glucuronide and 6-monoacetylmorphine (6-MAM) based on liquid chromatography–electrospray ionisation mass spectrometry is described. The drugs were analysed in human autopsy whole blood

Agnes Dienes-Nagy; Laurent Rivier; Christian Giroud; Marc Augsburger; Patrice Mangin

1999-01-01

75

Molecular Structure of Ethyl maltol  

NSDL National Science Digital Library

Ethyl maltol was discovered in the 1970s. It was originally isolated from larch tree bark and is produced through fermentation-organic synthesis. Ethyl maltol occurs naturally in cereal, bread crust, coffee, and cocoa. This substance is also used as a flavor enhancer because it tends to mask bad tasting chemicals, and heightens richness and creaminess. The compound has been employed as a flavor enhancer in wine, chocolate, vanilla, fruit flavored drinks, pastries, candy, tobacco, cosmetics, and medicines.

2002-10-11

76

A tale of a rich cluster at z$\\sim$0.8 as seen by the Star Formation Histories of its ETGs  

E-print Network

We present a detailed stellar population analysis for a sample of 24 early-type galaxies belonging to the rich cluster RXJ0152.7-1357 at z=0.83. We have derived the age, metallicity, abundance pattern and star formation history for each galaxy individually, to further characterize this intermediate-z reference cluster. We then study how these stellar population parameters depend on local environment. This provides a better understanding on the formation timescales and subsequent evolution of the substructures in this cluster. We have also explored the evolutionary link between z$\\sim$0.8 ETGs and those in the local Universe by comparing the trends that the stellar population parameters follow with galaxy velocity dispersion at each epoch. We find that the ETGs in Coma are consistent with being the (passively-evolving) descendants of the ETG population in RXJ10152.7-1357. Furthermore, our results favor a downsizing picture, where the subclumps centers were formed first. This central parts contain the most mass...

Ferré-Mateu, Anna; Vazdekis, Alexandre; de la Rosa, Ignacio G

2014-01-01

77

An Orphan Esterase ABHD10 Modulates Probenecid Acyl Glucuronidation in Human Liver.  

PubMed

Probenecid, a widely used uricosuric agent, is mainly metabolized to probenecid acyl glucuronide (PRAG), which is considered a causal substance of severe allergic or anaphylactoid reactions. PRAG can be hydrolyzed (deglucuronidated) to probenecid. The purpose of this study was to identify enzymes responsible for probenecid acyl glucuronidation and PRAG deglucuronidation in human livers and to examine the effect of deglucuronidation in PRAG formation. In human liver homogenates (HLHs), the intrinsic clearance (CLint) of PRAG deglucuronidation was much greater (497-fold) than that of probenecid acyl glucuronidation. Evaluation of PRAG formation by recombinant UDP-glucuronosyltransferase (UGT) isoforms and an inhibition study using HLHs as an enzyme source demonstrated that multiple UGT isoforms, including UGT1A1, UGT1A9, and UGT2B7, catalyzed probenecid acyl glucuronidation. We found that recombinant ?/? hydrolase domain containing 10 (ABHD10) substantially catalyzed PRAG deglucuronidation activity, whereas carboxylesterases did not. Similar inhibitory patterns by chemicals between HLHs and recombinant ABHD10 supported the major contribution of ABHD10 to PRAG deglucuronidation in human liver. Interestingly, it was demonstrated that the CLint value of probenecid acyl glucuronidation in HLHs was increased by 1.7-fold in the presence of phenylmethylsulfonyl fluoride, which potently inhibited ABHD10 activity. In conclusion, we found that PRAG deglucuronidation catalyzed by ABHD10 suppressively regulates PRAG formation via multiple UGT enzymes in human liver. The balance of activities by these enzymes is important for the formation of PRAG, which may be associated with the adverse reactions observed after probenecid administration. PMID:25217485

Ito, Yusuke; Fukami, Tatsuki; Yokoi, Tsuyoshi; Nakajima, Miki

2014-12-01

78

Ethyl diazoacetate synthesis in flow  

PubMed Central

Summary Ethyl diazoacetate is a versatile compound in organic chemistry and frequently used on lab scale. Its highly explosive nature, however, severely limits its use in industrial processes. The in-line coupling of microreactor synthesis and separation technology enables the synthesis of this compound in an inherently safe manner, thereby making it available on demand in sufficient quantities. Ethyl diazoacetate was prepared in a biphasic mixture comprising an aqueous solution of glycine ethyl ester, sodium nitrite and dichloromethane. Optimization of the reaction was focused on decreasing the residence time with the smallest amount of sodium nitrite possible. With these boundary conditions, a production yield of 20 g EDA day?1 was achieved using a microreactor with an internal volume of 100 ?L. Straightforward scale-up or scale-out of microreactor technology renders this method viable for industrial application. PMID:24062847

Delville, Marielle M E; van Hest, Jan C M

2013-01-01

79

Contribution of morphine and morphine-6-glucuronide to respiratory depression in a child.  

PubMed

A morphine plasma concentration/respiratory rate relationship has been described for both adults and children although that of its metabolite, morphine-6-glucuronide, remains uncertain. We describe this relationship in a child with end-stage renal failure who received repeat morphine administration over two days. An EMAX model for additive morphine and morphine-6-glucuronide respiratory effects described respiratory rate better than models describing either alone. Failure to clear morphine-6-glucuronide renally led to respiratory depression episodes occurring later than those predicted by modelling morphine levels only. These findings support the use of alternative analgesics (e.g. fentanyl) that are cleared by non-renal pathways and have no active metabolites in patients with end-stage renal disease. PMID:22934872

Hannam, J A; Anderson, B J

2012-09-01

80

5?-Androst-16-en-3?-ol ?-D-glucuronide, precursor of 5?-androst-16-en-3?-ol in human sweat.  

PubMed

5?-Androst-16-en-3?-ol (?-androstenol) is an important contributor to human axilla sweat odor. It is assumed that ?-andostenol is excreted from the apocrine glands via a H2 O-soluble conjugate, and this precursor was formally characterized in this study for the first time in human sweat. The possible H2 O-soluble precursors, sulfate and glucuronide derivatives, were synthesized as analytical standards, i.e., ?-androstenol, ?-androstenol sulfates, 5?-androsta-5,16-dien-3?-ol (?-androstadienol) sulfate, ?-androstenol ?-glucuronide, ?-androstenol ?-glucuronide, ?-androstadienol ?-glucuronide, and ?-androstenol ?-glucuronide furanose. The occurrence of ?-androstenol ?-glucuronide was established by ultra performance liquid chromatography (UPLC)/MS (heated electrospray ionization (HESI)) in negative-ion mode in pooled human sweat, containing eccrine and apocrine secretions and collected from 25 female and 24 male underarms. Its concentration was of 79?ng/ml in female secretions and 241?ng/ml in male secretions. The release of ?-androstenol was observed after incubation of the sterile human sweat or ?-androstenol ?-glucuronide with a commercial glucuronidase enzyme, the urine-isolated bacteria Streptococcus agalactiae, and the skin bacteria Staphylococcus warneri DSM 20316, Staphylococcus haemolyticus DSM 20263, and Propionibacterium acnes ATCC 6919, reported to have ?-glucuronidase activities. We demonstrated that if ?- and ?-androstenols and androstadienol sulfates were present in human sweat, their concentrations would be too low to be considered as potential precursors of malodors; therefore, the H2 O-soluble precursor of ?-androstenol in apocrine secretion should be a ?-glucuronide. PMID:24327440

Starkenmann, Christian; Mayenzet, Fabienne; Brauchli, Robert; Troccaz, Myriam

2013-12-01

81

Placental transfer and fetal elimination of morphine-3-?-glucuronide in the pregnant baboon  

PubMed Central

The glucuronide metabolites of several widely used drugs are detected in fetal plasma following maternal drug administration. However, the disposition of these metabolites is poorly understood and clinical concerns have been raised about accumulation of active metabolites in the fetus. For this reason, morphine-3-?-glucuronide (M3G), an active metabolite of morphine, was studied to provide quantitative data on disposition. Maternal, fetal, and bi-directional placental clearances of M3G were measured in 3 pregnant baboons. During maternal infusion of M3G to steady-state, the glucuronide metabolite readily appeared in fetal plasma achieving a mean (± SD) fetal-to-maternal concentration ratio of 0.79 ± 0.04. In paired maternal and fetal infusions, steady-state clearances (mean ± SD) were 53 ± 3 (maternal), 1.5 ± 0.5 (maternal-to-fetal), 2.6 ± 0.1 (fetal-to-maternal), and ?0.70 ± 0.6 ml·min?1 (fetal). These clearance values support bidirectional transfer of M3G across the placenta and indicate negligible direct clearance from the fetus. The clearance of M3G across the placenta is more than twenty-fold less than that of morphine. Despite this low index of permeability, placental transfer contributes significantly to the glucuronide pool in the fetus. Placental transfer emerges as the major clearance pathway for the glucuronide from the fetus and suggests a component of active efflux. What is more, the results do not support the concept of sequestration in the fetal intestine as a significant route of clearance. Together these results clarify the distribution and clearance of glucuronides in the pregnant primate and facilitate prediction of fetal exposure to active metabolites. PMID:18566040

Garland, Marianne; Abildskov, Kirsten M.; Kiu, Tung-wah; Daniel, Salha S.; Weldy, Piper; Stark, Raymond I.

2008-01-01

82

The C-glycosyl flavonoid, aspalathin, is absorbed, methylated and glucuronidated intact in humans.  

PubMed

Human bioavailability of the flavonoid dihydrochalcones is little understood, and no evidence exists for C-glycosyl flavonoid absorption in humans. The present study uses catechol-O-methyltransferase to generate methylated metabolites of aspalathin (a C-glycosyl dihydrochalcone from rooibos tea). One of the methylated forms, both with and without glucuronidation, was detected using LC-MS/MS in the urine of human subjects (n = 6), demonstrating that deglycosylation is not a prerequisite for C-glycosyl flavonoid absorption. Methylation is catalysed by both intestine and liver cytosolic extracts. The results show that flavonoid C-glycosides are methylated and glucuronidated in vivo in an intact form in humans. PMID:19653227

Courts, Fraser L; Williamson, Gary

2009-09-01

83

Inhibition of glucuronidation of benzo(a)pyrene phenols by long-chain fatty acids.  

PubMed

Long-chain fatty acids inhibit glucuronidation of benzo(a)pyrene phenols in perfused liver; therefore, this study was designed to investigate interactions of fatty acids with beta-glucuronidase, glucuronosyl transferase, and energy supply. In beta-glucuronidase-deficient C3H/He mice, infusion of oleate (250 microM) increased the release of free benzo(a)pyrene phenols from 14 to 33 nmol/g/h and decreased release of glucuronides into the perfusate from 25 to 17 nmol/g/h. Rates of accumulation of glucuronides in the liver were also diminished from 11 to 4 nmol/g/h after infusion of oleate (250 microM). Fatty acids did not affect the release of benzo(a)pyrene metabolites into bile, and the ratio of free phenol to glucuronide production was increased from 0.57 to 1.30. A similar trend was observed in livers from DBA/2 mice that have beta-glucuronidase. Rates of hydrolysis of benzo(a)pyrene-O-glucuronide were not altered in isolated microsomes by addition of oleoyl coenzyme A (CoA) or octanoyl CoA (10- approximately 100 microM). Thus, we conclude that fatty acids do not alter glucuronidation by acting on beta-glucuronidase. The concentration of cofactors (UDP-glucuronic acid, UDP-glucose, and adenine nucleotides) involved in hepatic conjugation was not altered by infusion of concentrations of oleate (300 microM) that inhibited glucuronidation in perfused livers. When oleate concentrations were increased to 600 microM, UDP-glucuronic acid and UDP-glucose decreased 44 and 49%, respectively, and the ATP:ADP ratio declined concomitantly. Oleoyl CoA inhibited UDP-glucuronosyl transferase noncompetitively (half-maximal inhibition, 10 microM) in microsomes with 3-hydroxy-benzo(a)pyrene or p-nitrophenol as substrate. In contrast, octanoyl CoA was a very poor inhibitor of transferase activity. Inhibition of the transferase by oleoyl CoA was increased markedly by treatment with detergents (Triton X-100), i.e., half-inhibition of glucuronosyl transferase was obtained with about 2 microM oleoyl CoA. Inhibition of UDP-glucuronosyl transferase by oleoyl CoA was also increased in a dose-dependent manner by albumin, possibly due to increasing access of the CoA derivative to the enzyme. Collectively, these data indicate that fatty acids diminish glucuronidation via the formation of acyl CoA compounds that inhibit UDP-glucuronosyl transferase noncompetitively. PMID:1908348

Zhong, Z; Kauffman, F C; Thurman, R G

1991-09-01

84

Molecular Structure of Ethyl cyclotene  

NSDL National Science Digital Library

Ethyl Cyclotene has a similar odor and flavor to Cyclotene. It is naturally found in coffee and tobacco. As a food additive, this compound has a very strong maple odor and taste. It contributes to the fragrance of rum and whiskey.

2006-09-18

85

Detection of interstellar ethyl cyanide  

NASA Technical Reports Server (NTRS)

Twenty-four millimeter-wave emission lines of ethyl cyanide (CH3CH2CN) have been detected in the Orion Nebula (OMC-1) and seven in Sgr B2. To derive precise radial velocities from the astronomical data, a laboratory measurement of the rotational spectrum of ethyl cyanide has been made at frequencies above 41 GHz. In OMC-1, the rotational temperature of ethyl cyanide is 90 K (in good agreement with other molecules), the local-standard-of-rest radial velocity is 4.5 + or - 1.0 km/s (versus 8.5 km/s for most molecules), and the column density is 1.8 by 10 to the 14th power per sq cm (a surprisingly high figure for a complicated molecule). The high abundance of ethyl cyanide in the Orion Nebula suggests that ethane and perhaps larger saturated hydrocarbons may be common constituents of molecular clouds and have escaped detection only because they are nonpolar or only weakly polar.

Johnson, D. R.; Lovas, F. J.; Gottlieb, C. A.; Gottlieb, E. W.; Litvak, M. M.; Thaddeus, P.; Guelin, M.

1977-01-01

86

EVALUATION OF INDOXYL-B-D GLUCURONIDE AS A CHROMOGEN IN MEDIA SPECIFIC FOR ESCHERICHIA COLI  

EPA Science Inventory

Indoxyl-beta D-glucuronide was evaluated as a specific chromogen for detection of Escherichia coli by the membrane filter method. n all 487 colonies were tested from the indoxyl supplemented media yielding 82.9% verification as E. coli. ompared to the indoxyl medium other media p...

87

The Escherichia coli glucuronylsynthase promoted synthesis of steroid glucuronides: improved practicality and broader scope.  

PubMed

A library of steroid glucuronides was prepared using the glucuronylsynthase derived from Escherichia coli?-glucuronidase, followed by purification using solid-phase extraction. A representative range of steroid substrates were screened for synthesis on the milligram scale under optimised conditions with conversions dependent on steroid substitution and stereochemistry. Epiandrosterone (3?-hydroxy-5?-androstan-17-one) provided the highest conversion of 90% (84% isolated yield). The previously unreported glucuronide conjugates of methandriol (17?-methylandrost-5-ene-3?,17?-diol), cholest-5-ene-3?,25-diol and the designer steroid trenazone (17?-hydroxyestra-4,9-dien-3-one) were prepared on a multi-milligram scale suitable for characterisation by (1)H and (13)C NMR spectroscopy. The glucuronide conjugate of d5-etiocholanolone (2,2,3,4,4-d5-3?-hydroxy-5?-androstan-17-one), a target developed by the World Anti-Doping Agency as a certified reference material, was also prepared on a milligram scale. The improved E. coli glucuronylsynthase method provides for the rapid synthesis and purification of steroid glucuronides on a scale suitable for a range of analytical applications. PMID:25001892

Ma, Paul; Kanizaj, Nicholas; Chan, Shu-Ann; Ollis, David L; McLeod, Malcolm D

2014-08-28

88

Profiling serum bile acid glucuronides in humans: gender divergences, genetic determinants, and response to fenofibrate.  

PubMed

Glucuronidation, catalyzed by uridine 5'-diphospho-glucuronosyltransferase (UGT) enzymes, detoxifies cholestatic bile acids (BAs). We aimed to (i) characterize the circulating BA-glucuronide (BA-G) pool composition in humans, (ii) determine how sex and UGT polymorphisms influence this composition, and (iii) analyze the effects of the lipid-lowering drug fenofibrate on the circulating BA-G profile in 300 volunteers and 5 cholestatic patients. Eleven BA-Gs were determined in pre- and postfenofibrate samples. Men exhibited higher BA-G concentrations, and various genotype/BA-G associations were discovered in relevant UGT genes. The chenodeoxycholic acid-3G (CDCA-3G) concentration was associated with the UGT2B7 802C>T polymorphism. Glucuronidation assays confirmed the predominant role of UGT2B7 and UGT1A4 in CDCA-3G formation. Fenofibrate exposure increased the serum levels of five BA-G species, including CDCA-3G, and upregulated expression of UGT1A4, but not UGT2B7, in hepatic cells. This study demonstrated that fenofibrate stimulates BA glucuronidation in humans and thus reduces BA toxicity in the liver. PMID:23756370

Trottier, J; Perreault, M; Rudkowska, I; Levy, C; Dallaire-Theroux, A; Verreault, M; Caron, P; Staels, B; Vohl, M-C; Straka, R J; Barbier, O

2013-10-01

89

A New Strategy to Rapidly Evaluate Kinetics of Glucuronide Efflux by Breast Cancer Resistance Protein (BCRP/ABCG2)  

PubMed Central

Purpose The efflux transporter breast cancer resistance protein (BCRP/ABCG2) plays an important role in excretion of anionic drugs and metabolites including glucuronides in humans. Methods In this article, our recently published cell model (i.e., HeLa cells over-expressing UGT1A9 (HeLa1A9)) is used to determine the kinetic parameters of BCRP-mediated transport of glucuronides. Results After incubation of the aglycone with the cells, a steady-state (i.e., zero-order or near zero-order) excretion of its glucuronide is rapidly achieved and then maintained. Kinetic profiling with different (intracellular) glucuronide concentrations and their corresponding excretion rates is enabled by varying the concentration of the aglycone, which allows for the determination of kinetic parameters responsible for BCRP-mediated efflux of glucuronides. This approach was validated theoretically using a cellular pharmacokinetic model incorporating various enzymatic and transporter-mediated kinetic processes. It was also validated experimentally in that kinetic parameters of efflux of glucuronides of 6-hydroxyflavone and 4-methylumberiferone in the HeLa1A9 cell model were shown to be consistent with those derived with BCRP-overexpressing membrane vesicles. Conclusion This study provides a new strategy for rapidly evaluating the kinetics of glucuronide efflux by BCRP. PMID:22752253

Wu, Baojian; Jiang, Wen; Yin, Taijun; Gao, Song

2013-01-01

90

Biotransformation of Bisphenol AF to Its Major Glucuronide Metabolite Reduces Estrogenic Activity  

PubMed Central

Bisphenol AF (BPAF), an endocrine disrupting chemical, can induce estrogenic activity through binding to estrogen receptor (ER). However, the metabolism of BPAF in vivo and the estrogenic activity of its metabolites remain unknown. In the present study, we identified four metabolites including BPAF diglucuronide, BPAF glucuronide (BPAF-G), BPAF glucuronide dehydrated and BPAF sulfate in the urine of Sprague-Dawley (SD) rats. BPAF-G was further characterized by nuclear magnetic resonance (NMR). After treatment with a single dose of BPAF, BPAF was metabolized rapidly to BPAF-G, as detected in the plasma of SD rats. Biotransformation of BPAF to BPAF-G was confirmed with human liver microsomes (HLM), and Vmax of glucuronidation for HLM was 11.6 nmol/min/mg. We also found that BPAF glucuronidation could be mediated through several human recombinant UDP-glucuronosyltransferases (UGTs) including UGT1A1, UGT1A3, UGT1A8, UGT1A9, UGT2B4, UGT2B7, UGT2B15 and UGT2B17, among which UGT2B7 showed the highest efficiency of glucuronidation. To explain the biological function of BPAF biotransformation, the estrogenic activities of BPAF and BPAF-G were evaluated in ER-positive breast cancer T47D and MCF7 cells. BPAF significantly stimulates ER-regulated gene expression and cell proliferation at the dose of 100 nM and 1 ?M in breast cancer cells. However, BPAF-G did not show any induction of estrogenic activity at the same dosages, implying that formation of BPAF-G is a potential host defense mechanism against BPAF. Based on our study, biotransformation of BPAF to BPAF-G can eliminate BPAF-induced estrogenic activity, which is therefore considered as reducing the potential threat to human beings. PMID:24349450

Yin, Jie; Zhang, Jing; Feng, Yixing; Shao, Bing

2013-01-01

91

Mitochondrial Dysfunction Leads to Deconjugation of Quercetin Glucuronides in Inflammatory Macrophages  

PubMed Central

Dietary flavonoids, such as quercetin, have long been recognized to protect blood vessels from atherogenic inflammation by yet unknown mechanisms. We have previously discovered the specific localization of quercetin-3-O-glucuronide (Q3GA), a phase II metabolite of quercetin, in macrophage cells in the human atherosclerotic lesions, but the biological significance is poorly understood. We have now demonstrated the molecular basis of the interaction between quercetin glucuronides and macrophages, leading to deconjugation of the glucuronides into the active aglycone. In vitro experiments showed that Q3GA was bound to the cell surface proteins of macrophages through anion binding and was readily deconjugated into the aglycone. It is of interest that the macrophage-mediated deconjugation of Q3GA was significantly enhanced upon inflammatory activation by lipopolysaccharide (LPS). Zymography and immunoblotting analysis revealed that ?-glucuronidase is the major enzyme responsible for the deglucuronidation, whereas the secretion rate was not affected after LPS treatment. We found that extracellular acidification, which is required for the activity of ?-glucuronidase, was significantly induced upon LPS treatment and was due to the increased lactate secretion associated with mitochondrial dysfunction. In addition, the ?-glucuronidase secretion, which is triggered by intracellular calcium ions, was also induced by mitochondria dysfunction characterized using antimycin-A (a mitochondrial inhibitor) and siRNA-knockdown of Atg7 (an essential gene for autophagy). The deconjugated aglycone, quercetin, acts as an anti-inflammatory agent in the stimulated macrophages by inhibiting the c-Jun N-terminal kinase activation, whereas Q3GA acts only in the presence of extracellular ?-glucuronidase activity. Finally, we demonstrated the deconjugation of quercetin glucuronides including the sulfoglucuronides in vivo in the spleen of mice challenged with LPS. These results showed that mitochondrial dysfunction plays a crucial role in the deconjugation of quercetin glucuronides in macrophages. Collectively, this study contributes to clarifying the mechanism responsible for the anti-inflammatory activity of dietary flavonoids within the inflammation sites. PMID:24260490

Miki, Satomi; Shiba, Yuko; Minekawa, Shoko; Nishikawa, Tomomi; Mukai, Rie; Terao, Junji; Kawai, Yoshichika

2013-01-01

92

Nicotine glucuronidation and the human UDP-glucuronosyltransferase UGT2B10.  

PubMed

Nicotine biotransformation affects the smoking habits of addicted individuals and therefore their health risk. Using an improved analytical method, we have discovered that the human UDP-glucuronosyltransferase (UGT) 2B10, a liver enzyme previously unknown to conjugate nicotine or exhibit considerable activity toward any compound, plays a major role in nicotine inactivation by direct conjugation with glucuronic acid at the aromatic nitrogen atom. The K(m) value of recombinant UGT2B10 for nicotine (0.29 mM) was similar to that determined for human liver microsomes (0.33 mM), whereas the K(m) value of UGT1A4 for nicotine was almost 10-fold greater (2.4 mM). UGT2B10 was also more active than UGT1A4 in N-glucuronidation of cotinine (oxidative nicotine metabolite), whereas UGT2B7 exhibited only low nicotine glucuronidation activity and was essentially inactive toward cotinine. UGT1A9 did not glucuronidate nicotine or cotinine. Quantitative reverse transcription-polymerase chain reaction showed that UGT2B10 mRNA was exclusively expressed in human liver, whereas UGTs 1A4 and 2B7 were expressed at comparable, although somewhat lower, levels in liver and several other extrahepatic tissues, including kidney and intestine. These findings for UGT2B10 (but not for UGT1A4 and UGT2B7) were mirrored by human tissue activities because nicotine and cotinine glucuronidation rates in intestine microsomes were less than 0.1% that of human liver microsomes. These novel findings solve two seemingly separate questions: which UGT is primarily responsible for nicotine glucuronidation in human liver, and what conjugation reactions are catalyzed by UGT2B10. PMID:17576790

Kaivosaari, Sanna; Toivonen, Päivi; Hesse, Leah M; Koskinen, Mikko; Court, Michael H; Finel, Moshe

2007-09-01

93

Glucuronidation and Covalent Protein Binding of Benoxaprofen and Flunoxaprofen in Sandwich-Cultured Rat and Human Hepatocytes  

PubMed Central

Benoxaprofen (BNX), a nonsteroidal anti-inflammatory drug (NSAID) that was withdrawn because of hepatotoxicity, is more toxic than its structural analog flunoxaprofen (FLX) in humans and rats. Acyl glucuronides have been hypothesized to be reactive metabolites and may be associated with toxicity. Both time- and concentration-dependent glucuronidation and covalent binding of BNX, FLX, and ibuprofen (IBP) were determined by exposing sandwich-cultured rat hepatocytes to each NSAID. The levels of glucuronide and covalent protein adduct measured in cells followed the order BNX > FLX > IBP. These results indicate that 1) BNX-glucuronide (G) is more reactive than FLX-G, and 2) IBP-G is the least reactive metabolite, which support previous in vivo studies in rats. The proportional increases of protein adduct formation for BNX, FLX, and IBP as acyl glucuronidation increased also support the hypothesis that part of the covalent binding of all three NSAIDs to hepatic proteins is acyl glucuronide-dependent. Moreover, theses studies confirmed the feasibility of using sandwich-cultured rat hepatocytes for studying glucuronidation and covalent binding to hepatocellular proteins. These studies also showed that these in vitro methods can be applied using human tissues for the study of acyl glucuronide reactivity. More BNX-protein adduct was formed in sandwich-cultured human hepatocytes than FLX-protein adduct, which not only agreed with its relative toxicity in humans but also was consistent with the in vitro findings using rat hepatocyte cultures. These data support the use of sandwich-cultured human hepatocytes as an in vitro screening model of acyl glucuronide exposure and reactivity. PMID:19773537

Dong, Jennifer Q.

2009-01-01

94

Interpretation problems in a forensic case of abstinence determination using alcohol markers in hair  

Microsoft Academic Search

In a child custody case a mother with a longstanding history of alcohol misuse had to show absolute abstinence for one year. She entered a residential rehabilitation for six months and was tested two months later by way of a hair test for ethyl glucuronide (EtG) with the result of 22pg\\/mg in the proximal 0–1cm segment and the segments 1–2cm

Fritz Pragst

95

Keap1 Recruits Neh2 through Binding to ETGE and DLG Motifs: Characterization of the Two-Site Molecular Recognition Model  

PubMed Central

The expression of the phase 2 detoxification enzymes and antioxidant proteins is induced at the transcriptional level by Nrf2 and negatively regulated at the posttranslational level by Keap1 through protein-protein interactions with and subsequent proteolysis of Nrf2. We found that the Neh2 domain of Nrf2 is an intrinsically disordered but biologically active regulatory domain containing a 33-residue central ?-helix followed by a mini antiparallel ?-sheet. Isothermal calorimetry analysis indicated that one Neh2 molecule interacts with two molecules of Keap1 via two binding sites, the stronger binding ETGE motif and the weaker binding DLG motif. Nuclear magnetic resonance titration study showed that these two motifs of the Neh2 domain bind to an overlapping site on the bottom surface of the ?-propeller structure of Keap1. In contrast, the central ?-helix of the Neh2 domain does not have any observable affinity to Keap1, suggesting that this region may serve as a bridge connecting the two motifs for the association with the two ?-propeller structures of a dimer of Keap1. Based on these observations, we propose that Keap1 recruits Nrf2 by the ETGE motif and that the DLG motif of the Neh2 domain locks its lysine-rich central ?-helix in a correct position to benefit ubiquitin signaling. PMID:16581765

Tong, Kit I.; Katoh, Yasutake; Kusunoki, Hideki; Itoh, Ken; Tanaka, Toshiyuki; Yamamoto, Masayuki

2006-01-01

96

Nitrosation of glycine ethyl ester and ethyl diazoacetate to give the alkylating agent and mutagen ethyl chloro(hydroximino)acetate.  

PubMed

Whereas nitrosation of secondary amines produces nitrosamines, amino acids with primary amino groups and glycine ethyl ester were reported to react with nitrite to give unidentified agents that alkylated 4-(p-nitrobenzyl)pyridine to produce purple dyes and be direct mutagens in the Ames test. We report here that treatment of glycine ethyl ester at 37 degrees C with excess nitrite acidified with HCl, followed by ether extraction, gave 30-40% yields of a product identified as ethyl chloro(hydroximino)acetate [ClC(=NOH)COOEt, ECHA] and a 9% yield of ethyl chloroacetate. The ECHA was identical to that synthesized by a known method from ethyl acetoacetate, strongly alkylated nitrobenzylpyridine, and may have arisen by N-nitrosation of glycine ethyl ester to give ethyl diazoacetate, which was C-nitrosated and reacted with chloride to give ECHA. Nitrosation of ethyl diazoacetate also yielded ECHA. Ethyl nitroacetate was not an intermediate as its nitrosation did not produce ECHA. ECHA reacted with aniline to give ethyl (hydroxamino)(phenylimino)acetate [PhN=C(NHOH)CO2Et]. This product was different from ethyl [(phenylamino)carbonyl]carbamate [PhNHC(=O)NHCO2Et], which was synthesized by reacting ethyl isocyanatoformate (OCN.CO2Et) with aniline. ECHA reacted with guanosine to give a derivative, which may have been a guanine-C(=NOH)CO2Et derivative. ECHA showed moderate toxicity and weak but significant mutagenicity without activation in Salmonella typhimurium TA-100 (mean, 1.31 x control value for 12-18 microg/plats) and for V79 mammalian cells (1.5-1.7 x control value for 60-100 microM). In conclusion, gastric nitrosation of glycine derivatives such as peptides with a N-terminal glycine might produce ECHA analogues that alkylate bases of gastric mucosal DNA and thereby initiate gastric cancer. PMID:15025513

Zhou, Lin; Haorah, James; Chen, Sheng C; Wang, Xiaojie; Kolar, Carol; Lawson, Terence A; Mirvish, Sidney S

2004-03-01

97

Molecular Structure of Ethyl acetate  

NSDL National Science Digital Library

Ethyl acetate is a colorless, volatile liquid with a mild and fragrant odor. It is used as solvent in chemistry laboratories but can also be found in many household products such as paints, coatings, and adhesives. The compound is also used in some extraction processes such as decaffeination or purification of antibiotics. It is present in both nail polish and removers. Some synthetic fruit essences may contain this and other esters. Etymologists like to use this solvent for insect collecting as the vapor kill the insect quickly and keep it soft for mounting.

2006-03-08

98

Morphine6Glucuronide: Morphine??s Successor for Postoperative Pain Relief?  

Microsoft Academic Search

In searching for an analgesic with fewer side effects than morphine, examination of morphine's active metabolite, morphine-6-glucuronide (M6G), sug- gests that M6G is possibly such a drug. In contrast to morphine, M6G is not metabolized but excreted via the kidneys and exhibits enterohepatic cycling, as it is a substrate for multidrug resistance transporter pro- teins in the liver and intestines.

Eveline L. A. van Dorp; Raymonda Romberg; Elise Sarton; James G. Bovill; Albert Dahan

2006-01-01

99

Hepatic glucuronidation of isoneochamaejasmin a from the traditional Chinese medicine Stellera chamaejasme L. Root.  

PubMed

Isoneochamaejasmin A (INCA), a biflavonoid, is one of main active ingredients in the dried root of Stellera chamaejasme L., a widely used traditional Chinese medicine. In the present study, we identified the glucuronidation metabolite of INCA and characterized the UDP glucuronosyltransferases (UGTs) responsible for INCA glucuronidation. 7-O-glucuronide (M1) and 4'-O-glucuronide (M2) were identified by incubation of INCA with human liver microsomes (HLMs) in the presence of UDP glucuronic acid, and their structures were confirmed by high-resolution mass spectrometry and nuclear magnetic resonance analyses. Although INCA is a single enantiomer molecule, its M1 metabolite showed two equal-size peaks on a ?NAP stationary phase but only one peak on a C(18) stationary phase, indicating that the 7-/7''- and 4'-/4'''-hydroxyl groups of INCA were in different spatial configurations relative to each other. Among the recombinant human UGT isoform test and correlation analysis, UGT1A1, UGT1A3, and UGT1A9 were found to mediate M1 formation, whereas only UGT1A3 mediated M2 formation. Kinetic studies showed obvious species differences between human, mouse, rat, dog, and pig liver microsomes. UGT1A1, HLMs, and human intestinal microsomes, but not human kidney microsomes, exhibited substrate inhibition for the formation of M1. UGT1A1-mediated formation of M1 showed a 6- and 11-fold higher V(max) than did UGT1A3- and UGT1A9-mediated formation of M1, respectively. The results of the relative activity factor assay showed that UGT1A1 contributed approximately 75% in the formation of M1. These findings collectively indicate that UGT1A1 is the major enzyme in the formation of M1, whereas UGT1A3 is the major enzyme in the formation of M2. PMID:24452863

Yu, Lushan; Pu, Jianbin; Zuo, Minjuan; Zhang, Xia; Cao, Yang; Chen, Shifeng; Lou, Yan; Zhou, Quan; Hu, Haihong; Jiang, Huidi; Chen, Jianzhong; Zeng, Su

2014-04-01

100

Hesperidin metabolite hesperetin-7-O-glucuronide, but not hesperetin-3'-O-glucuronide, exerts hypotensive, vasodilatory, and anti-inflammatory activities.  

PubMed

Orally ingested hesperidin (HES) is hydrolyzed into hesperetin in the gastrointestinal tract and conjugated during absorption. Hesperetin conjugates are the main circulating metabolites in human and rat plasma. We previously reported that glucosyl hesperidin (GHES), a water-soluble HES derivative, prevents hypertension via improvement of endothelial dysfunction in spontaneously hypertensive rats (SHRs). Although these hesperetin conjugates seem to be responsible for hypotensive and endothelium-dependent vasodilatory activities of dietary GHES, little is known about the mechanisms of action of these conjugated metabolites. Therefore, the aim of the present study was to investigate the effects of hesperetin-7-O-?-d-glucuronide (HPT7G) and hesperetin-3'-O-?-d-glucuronide (HPT3'G), which are the predominant HES metabolites in rat plasma, on blood pressure and endothelial function. Intravenous administration of HPT7G (5 mg kg(-1)) decreased blood pressure in anesthetized SHRs. HPT7G enhanced endothelium-dependent vasodilation in response to acetylcholine, but had no effect on endothelium-independent vasodilation in response to sodium nitroprusside (SNP) in aortas isolated from SHRs. HPT7G decreased hydrogen peroxide-induced intracellular adhesion molecule-1 and monocyte chemoattractant protein-1 mRNA expression in rat aortic endothelial cells. In contrast, HPT3'G had little effect on these parameters. In conclusion, HPT7G exerted hypotensive, vasodilatory and anti-inflammatory activities, similar to hesperetin and these effects are associated, in part, with the activity of GHES and HES to improve hypertension and endothelial dysfunction. PMID:23831969

Yamamoto, Masaki; Jokura, Hiroko; Hashizume, Koujiro; Ominami, Hideo; Shibuya, Yusuke; Suzuki, Atsushi; Hase, Tadashi; Shimotoyodome, Akira

2013-09-01

101

The effect of various drugs on the glucuronidation of zidovudine (azidothymidine; AZT) by human liver microsomes.  

PubMed Central

1. Zidovudine (3'-azido-3'-deoxythymidine; AZT) is the drug of proven efficacy available for the treatment of patients with AIDS or ARC. It is eliminated mainly by hepatic glucuronidation. Therefore, interference with this metabolic pathway may lead to enhancement of AZT effect or to increased toxicity of the drug. We have examined the effect of a number of drugs which themselves undergo glucuronidation on AZT conjugation by human liver microsomes in vitro. 2. AZT glucuronidation followed Michaelis-Menten kinetics. The apparent Km and Vmax values (mean +/- s.d., n = 5), were 2.60 +/- 0.52 mM and 68.0 +/- 23.4 nmol h-1 mg-1, respectively, as determined from Eadie-Hofstee plots. 3. Dideoxyinosine, sulphanilamide and paracetamol were essentially non-inhibitory at concentrations up to 10 mM (4 times the concentration of AZT in the incubation). The most marked inhibitory effects were seen with indomethacin, naproxen, chloramphenicol, probenecid and ethinyloestradiol, with enzyme activity decreased by 97.7, 94.9, 88.7, 83.4% and 79.0%, respectively, at a concentration of 10 mM. Other compounds producing some inhibition of AZT conjugation were oxazepam, salicylic acid and acetylsalicylic acid. 4. Further studies are necessary to characterise the inhibition observed but the method described enables a screen of potentially important drug interactions to be carried out. PMID:1909542

Sim, S M; Back, D J; Breckenridge, A M

1991-01-01

102

Mechanism of peroxisome proliferator-activated receptor gamma (PPAR?) transactivation by hesperetin glucuronides is distinct from that by a thiazolidine-2,4-dione agent.  

PubMed

Hesperidin, a flavanone glycoside present abundantly in citrus fruits, is predominantly metabolized to hesperetin-7-O-?-D-glucuronide (H7-OG) and hesperetin-3'-O-?-D-glucuronide (H3'-OG), which exhibit partial agonistic activity towards peroxisome proliferator-activated receptor gamma (PPAR?). Here, in order to understand the mechanism(s) of action of PPAR? transactivation elicited by hesperetin glucuronides, we compared the transactivation activities of PPAR? (ligand-binding domain (LBD)) mutants by hesperetin glucuronides and troglitazone, a thiazolidine-2,4-dione class PPAR? full agonist. The assay results indicated that the mechanisms of activation of PPAR? by hesperetin glucuronides and by troglitazone are distinct, probably due to a difference in the binding sites of these compounds on the PPAR? LBD. Flavanone-class PPAR? partial agonists, luteolin and hesperetin glucuronides, showed similar activation profiles of the PPAR? LBD mutants, even though they have different side chain functionalities. PMID:24789933

Gamo, Kanae; Shiraki, Takuma; Matsuura, Nobuyasu; Miyachi, Hiroyuki

2014-01-01

103

40 CFR 180.441 - Quizalofop ethyl; tolerances for residues.  

Code of Federal Regulations, 2012 CFR

...Tolerances are established for residues of the herbicide quizalofop ethyl, including its...Tolerances are established for residues of the herbicide quizalofop ethyl, including...registration are established for residues of the herbicide quizalofop ethyl,...

2012-07-01

104

40 CFR 180.441 - Quizalofop ethyl; tolerances for residues.  

Code of Federal Regulations, 2013 CFR

...Tolerances are established for residues of the herbicide quizalofop ethyl, including its...Tolerances are established for residues of the herbicide quizalofop ethyl, including...registration are established for residues of the herbicide quizalofop ethyl,...

2013-07-01

105

Simultaneous Quantification of Free and Glucuronidated Cannabinoids in Human Urine by Liquid Chromatography-Tandem Mass Spectrometry  

PubMed Central

Background Cannabis is the most commonly abused drug of abuse and is commonly quantified during urine drug testing. We conducted a controlled drug administration studies investigating efficacy of urinary cannabinoid glucuronide metabolites for documenting recency of cannabis intake and for determining stability of urinary cannabinoids. Methods A liquid chromatography tandem mass spectrometry method was developed and validated quantifying ?9-tetrahydrocannabinol (THC), 11-hydroxy-THC (11-OH-THC), 11-nor-9-carboxy-THC (THCCOOH), cannabidiol, cannabinol, THC-glucuronide and THCCOOH-glucuronide in 0.5 ml human urine via supported-liquid extraction. Chromatography was performed on an Ultra Biphenyl column with a gradient of 10 mmol/l ammonium acetate, pH 6.15 and 15% methanol in acetonitrile at 0. 4ml/min. Analytes were monitored by positive and negative mode electrospray ionization and multiple reaction monitoring mass spectrometry. Results Linear ranges were 0.5–50 ng/ml for THC-glucuronide, 1–100 ng/ml for THCCOOH, 11-OH-THC and cannabidiol, 2–100 ng/ml for THC and cannabinol, and 5–500 ng/ml for THCCOOH-glucuronide (R2>0.99). Mean extraction efficiencies were 34–73% with analytical recovery (bias) 80.5–118.0% and total imprecision 3.0–10.2% coefficient of variation. Conclusion This method simultaneously quantifies urinary cannabinoids and phase II glucuronide metabolites, and enables evaluation of urinary cannabinoid glucuronides for documenting recency of cannabis intake and cannabinoid stability. The assay is applicable for routine urine cannabinoid testing. PMID:22771478

Scheidweiler, Karl B.; Desrosiers, Nathalie A.; Huestis, Marilyn A.

2012-01-01

106

Regiospecificity of Human UDP-glucuronosyltransferase Isoforms in Chalcone and Flavanone Glucuronidation Determined by Metal Complexation and Tandem Mass Spectrometry  

PubMed Central

The glucuronidation of a series of chalcones (2'-hydroxychalcone, 2',4'-dihydroxychalcone, 3,2'-dihydroxychalcone, 4,2'-dihydroxychalcone, and cardamonin) and their corresponding cyclized flavanones (7-hydroxyflavanone, 3'-hydroxyflavanone, 4'-hydroxyflavanone, and alpinetin) by nine human UDP-glucuronosyltransferase (UGT) 1A enzymes was evaluated. A post-column metal complexation LC-MS/MS strategy was used successfully to produce characteristic mass spectrometric product ions that were utilized in combination with elution order trends to identify chalcone and flavanone monoglucuronides unambiguously, thus allowing determination of the regioselectivities of the UGT1A isoforms. The presence of hydroxy groups on the A or B-ring had a significant effect on the glucuronide product yield and the site where glucuronidation occurred. For example, for reaction with UGT1A9, formation of the 2'-O-glucuronide was increased for dihydroxychalcones with A-ring hydroxy substituents. In contrast, although UGT1A8 reacted with 3,2'-dihydroxychalcone and 4,2'-dihydroxychalcone to yield 2'-O-glucuronide products, the presence of a B-ring hydroxy group at the 4' position on cardamonin and 2',4'-dihydroxychalcone quenched the reaction at the OH-2' position. Moreover, the A-ring OH-4 group promoted glucuronidation at the 2' position for the reaction of 4,2'-dihydroxychalcone with UGT1A1 and 1A3. For UGT1A7, hydroxy group substituents on the chalcone A-ring also promoted cyclization and formation of the corresponding flavanone glucuronide. PMID:23713759

Niemeyer, Emily D.; Brodbelt, Jennifer S.

2013-01-01

107

Inhibition of genistein glucuronidation by bisphenol A in human and rat liver microsomes.  

PubMed

Genistein is a natural phytoestrogen of the soybean, and bisphenol A (BPA) is a synthetic chemical used in the production of polycarbonate plastics. Both genistein and BPA disrupt the endocrine system in vivo and in vitro. Growing concerns of altered xenobiotic metabolism due to concomitant exposures from soy milk in BPA-laden baby bottles has warranted the investigation of the glucuronidation rate of genistein in the absence and presence (25 ?M) of BPA by human liver microsomes (HLM) and rat liver microsomes (RLM). HLM yield V(max) values of 0.93 ± 0.10 nmol · min(-1) · mg(-1) and 0.62 ± 0.05 nmol · min(-1) · mg(-1) in the absence and presence of BPA, respectively. K(m) values for genistein glucuronidation by HLM in the absence and presence of BPA are 15.1 ± 7.9 ?M and 21.5 ± 7.7 ?M, respectively, resulting in a K(i) value of 58.7 ?M for BPA. Significantly reduced V(max) and unchanged K(m) in the presence of BPA in HLM are suggestive of noncompetitive inhibition. In RLM, the presence of BPA resulted in a K(i) of 35.7 ?M, an insignificant change in V(max) (2.91 ± 0.26 nmol · min(-1) · mg(-1) and 3.05 ± 0.41 nmol · min(-1) · mg(-1) in the absence and presence of BPA, respectively), and an increase in apparent K(m) (49.4 ± 14 ?M with no BPA and 84.0 ± 28 ?M with BPA), indicative of competitive inhibition. These findings are significant because they suggest that BPA is capable of inhibiting the glucuronidation of genistein in vitro, and that the type of inhibition is different between HLM and RLM. PMID:22146138

Coughlin, Janis L; Thomas, Paul E; Buckley, Brian

2012-03-01

108

Influence of glucuronidation and reduction modifications of resveratrol on its biological activities.  

PubMed

Resveratrol (3,5,4'-trihydroxystilbene, RES), a star among dietary polyphenols, shows a wide range of biological activities, but it is rapidly and extensively metabolized into its glucuronide and sulfate conjugates as well as to the corresponding reduced products. This begs the question of whether the metabolites of RES contribute to its in vivo biological activity. To explore this possibility, we synthesized its glucuronidation (3-GR and 4'-GR) and reduction (DHR) metabolites, and evaluated the effect of these structure modifications on biological activities, including binding ability with human serum albumin (HSA), antioxidant activity in homogeneous solutions and heterogeneous media, anti-inflammatory activity, and cytotoxicity against various cancer cell lines. We found that 1) 4'-GR, DHR and RES show nearly equal binding to HSA, mainly through hydrogen bonding, whereas 3-GR adopts a quite different orientation mode upon binding, thereby resulting in reduced ability; 2) 3-GR shows comparable (even equal) ability to RES in FRAP- and AAPH-induced DNA strand breakage assays; DHR, 3-GR, and 4'-GR exhibit anti-hemolysis activity comparable to that of RES; additionally, 3-GR and DHR retain some degree activity of the parent molecule in DPPH.-scavenging and cupric ion-initiated oxidation of LDL assays, respectively; 3) compared to RES, 4'-GR displays equipotent ability in the inhibition of COX-2, and DHR presents comparable activity in inhibiting NO production and growth of SMMC-7721 cells. Relative to RES, its glucuronidation and reduction metabolites showed equal, comparable, or some degree of activity in the above assays, depending on the specific compound and test model, which probably supports their roles in contributing to the in vivo biological activities of the parent molecule. PMID:23703900

Lu, Dong-Liang; Ding, De-Jun; Yan, Wen-Jing; Li, Ran-Ran; Dai, Fang; Wang, Qi; Yu, Sha-Sha; Li, Yan; Jin, Xiao-Ling; Zhou, Bo

2013-06-17

109

Ethyl benzene from ethane and benzene  

SciTech Connect

A new process to produce ethyl benzene for styrene production by employing a new zeolite catalyst starting with ethane and benzene. The demand for styrene is projected to growth due to new polymer technology under development.

Pogue, R. [Dow Chemical Co., Freeport, TX (United States)

1996-10-01

110

Contrasting influences of glucuronidation and O-methylation of epicatechin on hydrogen peroxide-induced cell death in neurons and fibroblasts  

Microsoft Academic Search

The purpose of this study was to examine the comparative mechanisms by which the dietary form of the flavonoid epicatechin and its predominant in vivo metabolite, epicatechin glucuronide, influence oxidative stress-induced cell death in fibroblasts and neurons. The results demonstrate the contrasting influences of in vivo glucuronidation and methylation on the bioactivity of epicatechin.

Jeremy P. E Spencer; Hagen Schroeter; Andrew J Crossthwaithe; Gunter Kuhnle; Robert J Williams; Catherine Rice-Evans

2001-01-01

111

In vitro glucuronidation of Armillarisin A: UDP-glucuronosyltransferase 1A9 acts as a major contributor and significant species differences.  

PubMed

Abstract 1. This study is performed to investigate liver microsomal glucuronidation of Armillarisin A (A.A), an effective cholagogue drug, aiming at characterizing the involved UDP-glucuronosyltranferases (UGT) and revealing potential species differences. 2. A.A glucuronidation in human liver microsomes (HLM) generates one metabolite (M2) glucuronidated at the phenol hydroxyl group, obeying Michaelis-Menten kinetic model. Multiple isoforms including UGT1A1, 1A7, 1A9 and 2B15 can catalyze A.A glucuronidation. Kinetic assays and chemical inhibition studies both demonstrate that UGT1A9 is responsible for A.A glucuronidation in HLM. A.A glucuronidation in Cynomolgus monkey microsomes (CyLM) also follows Michaelis-Menten model, but can additionally catalyze the traced glucuronosyl substitution at the alcohol hydroxyl group (M1). The reactions in liver microsomes from Sprague-Dawley rats (RLM), ICR/CD-1 mouse (MLM), Beagle dog (DLM) all display biphasic kinetics and only M2 is detected. HLM, RLM and CyLM exhibit very similar catalytic activities towards A.A glucuronidation, with the intrinsic clearance values of respective 38, 37 and 37??L/min/mg, which are much higher than MLM and DLM. 3. This in vitro study indicates that UGT1A9 acts as a major contributor to A.A glucuronidation in human liver, and the reaction displays large species differences. PMID:24916899

Sun, Dongxue; Zhu, Liangliang; Xiao, Ling; Xia, Yangliu; Ge, Guangbo; Cao, Yunfeng; Wu, Yan; Yin, Jun; Yang, Ling

2014-11-01

112

Antimicrobial and demelanizing activity of Ganoderma lucidum extract, p-hydroxybenzoic and cinnamic acids and their synthetic acetylated glucuronide methyl esters.  

PubMed

Mushroom extracts or isolated compounds may be useful in the search of new potent antimicrobial agents. Herein, it is described the synthesis of protected (acetylated) glucuronide derivatives of p-hydroxybenzoic and cinnamic acids, two compounds identified in the medicinal mushroom Ganoderma lucidum. Their antimicrobial and demelanizing activities were evaluated and compared to the parent acids and G. lucidum extract. p-Hydroxybenzoic and cinnamic acids, as also their protected glucuronide derivatives revealed high antimicrobial (antibacterial and antifungal) activity, even better than the one showed by commercial standards. Despite the variation in the order of parent acids and the protected glucuronide derivatives, their antimicrobial activity was always higher than the one revealed by the extract. Nevertheless, the extract was the only one with demelanizing activity against Aspergillus niger. The acetylated glucuronide derivatives could be deprotected to obtain glucuronide metabolites, which circulate in the human organism as products of the metabolism of the parent compounds. PMID:23607932

Heleno, Sandrina A; Ferreira, Isabel C F R; Esteves, Ana P; ?iri?, Ana; Glamo?lija, Jasmina; Martins, Anabela; Sokovi?, Marina; Queiroz, Maria João R P

2013-08-01

113

Inhibitory effect of ciprofloxacin on ?-glucuronidase-mediated deconjugation of mycophenolic acid glucuronide.  

PubMed

The interaction between mycophenolate (MPA) and quinolone antibiotics such as ciprofloxacin is considered to reduce the enterohepatic recycling of MPA, which is biotransformed in the intestine from MPA glucuronide (MPAG) conjugate excreted via the biliary system; however, the molecular mechanism underlying this biotransformation of MPA is still unclear. In this study, an in vitro system was established to evaluate ?-glucuronidase-mediated deconjugation and to examine the influence of ciprofloxacin on the enzymatic deconjugation of MPAG and MPA resynthesis. Resynthesis of MPA via deconjugation of MPAG increased in a time-dependent manner from 5 to 60 min in the presence of ?-glucuronidase. Ciprofloxacin and phenolphthalein-?-d-glucuronide (PhePG), a typical ?-glucuronidase substrate, significantly decreased the production of MPA from MPAG in the ?-glucuronidase-mediated deconjugation system. In addition, enoxacin significantly inhibited the production of MPA from MPAG, while levofloxacin and ofloxacin had no inhibitory effect on MPA synthesis. Pharmacokinetic analysis revealed that ciprofloxacin showed a dose-dependent inhibitory effect on MPA production from MPAG via ?-glucuronidase with a half-maximal inhibitory concentration (IC50 ) value of 30.4 µm. While PhePG inhibited the ?-glucuronidase-mediated production of MPA from MPAG in a competitive manner, ciprofloxacin inhibited MPA synthesis via noncompetitive inhibition. These findings suggest that the reduction in the serum MPA concentration during the co-administration of ciprofloxacin is at least in part due to the decreased enterohepatic circulation of MPA because of noncompetitive inhibition of deconjugation of MPAG by intestinal ?-glucuronidase. PMID:24615849

Kodawara, Takaaki; Masuda, Satohiro; Yano, Yoshitaka; Matsubara, Kazuo; Nakamura, Toshiaki; Masada, Mikio

2014-07-01

114

Effect of chronic hypoxic hypoxia on oxidation and glucuronidation of carvedilol in rats.  

PubMed

Heart failure is accompanied with tissue (circulatory) hypoxia, and the metabolism of several drugs has been reported to be reduced in heart failure. The aim of this study was to investigate the effect of another type of respiratory hypoxia, hypoxic hypoxia (FiO2 15 % for 24 h followed by FiO2 10 % for 9 days) on the metabolism of carvedilol enantiomers in rats. Oxidation of carvedilol in rat liver microsomes was evaluated in the presence of reduced nicotinamide adenine dinucleotide phosphate, whereas glucuronidation was evaluated in the presence of UDP-glucuronic acid. Both oxidation and glucuronidation activities for two carvedilol enantiomers in hypoxic rat liver microsomes were similar to those in control rat liver microsomes. We also performed pharmacokinetic analysis of carvedilol enantiomers following intraportal infusion in control and hypoxic rats. The mean (±S.E.) portal clearance value of R- and S-carvedilol in control rats was 72 ± 16 and 156 ± 31 ml/min/kg, respectively, whereas that of the R- and S-enantiomers in hypoxic rats was 68 ± 8 and 113 ± 14 ml/min/kg, respectively. These findings indicated that the metabolism of carvedilol enantiomers was not significantly diminished in rats with chronic hypoxic hypoxia, and that other factor(s) besides hypoxia may be responsible for the reduced drug metabolism in heart failure. PMID:23739952

Yamaura, Shizuka; Fukao, Miki; Ishida, Kazuya; Taguchi, Masato; Hashimoto, Yukiya

2014-03-01

115

Evidence for covalent binding of acyl glucuronides to serum albumin via an imine mechanism as revealed by tandem mass spectrometry.  

PubMed Central

Acyl glucuronide metabolites of bilirubin and many drugs can react with serum albumin in vivo to form covalent adducts. Such adducts may be responsible for some toxic effects of carboxylic nonsteroidal antiinflammatory agents. The mechanism of formation of the adducts and their chemical structures are unknown. In this paper we describe the use of tandem mass spectrometry to locate binding sites and elucidate the binding mechanism involved in the formation of covalent adducts from tolmetin glucuronide and albumin in vitro. Human serum albumin and excess tolmetin glucuronide were coincubated in the presence of sodium cyanoborohydride to trap imine intermediates. The total protein product was reduced, carboxymethylated, and digested with trypsin. Six tolmetin-containing peptides (indicated by absorbance at 313 nm) were isolated by high-pressure liquid chromatography and analyzed by liquid secondary-ion mass spectrometry and collision-induced dissociation, using a four-sector tandem mass spectrometer. All six peptides contained tolmetin linked covalently via a glucuronic acid to protein lysine groups. Major attachment sites on the protein were Lys-195, -199, and -525; minor sites were identified as Lys-137, -351, and -541. Our results show unambiguously that the glucuronic acid moiety of acyl glucuronides can be retained within the structure when these reactive metabolites bind covalently to proteins, and they suggest that acyl migration followed by Schiff base (imine) formation is a credible mechanism for the generation of covalent adducts in vivo. PMID:8483897

Ding, A; Ojingwa, J C; McDonagh, A F; Burlingame, A L; Benet, L Z

1993-01-01

116

Integration of hepatic drug transporters and phase II metabolizing enzymes: Mechanisms of hepatic excretion of sulfate, glucuronide, and glutathione metabolites  

Microsoft Academic Search

The liver is the primary site of drug metabolism in the body. Typically, metabolic conversion of a drug results in inactivation, detoxification, and enhanced likelihood for excretion in urine or feces. Sulfation, glucuronidation, and glutathione conjugation represent the three most prevalent classes of phase II metabolism, which may occur directly on the parent compounds that contain appropriate structural motifs, or,

Maciej J. Zamek-Gliszczynski; Keith A. Hoffmaster; Ken-ichi Nezasa; Melanie N. Tallman; Kim L. R. Brouwer

2006-01-01

117

Human and Rat ABC Transporter Efflux of Bisphenol A and Bisphenol A Glucuronide: Interspecies Comparison and Implications for Pharmacokinetic Assessment  

EPA Science Inventory

Significant interspecies differences exist between human and rodent with respect to absorption, distribution, and excretion of bisphenol A (BPA) and its primary metabolite, BPA-glucuronide (BPA-G). ATP-Binding Cassette (ABC) transporter enzymes play important roles in these physi...

118

Mouse hepatoma cell lines differing in aryl hydrocarbon receptor-mediated signaling have different activities for glucuronidation.  

PubMed

For studies on the aryl hydrocarbon receptor (AhR)-dependent toxicity of the mycotoxins alternariol (AOH) and alternariol methyl ether (AME), three mouse hepatoma (Hepa-1) cell lines with intact and with compromised AhR signaling were compared with respect to their activities for hydroxylation, methylation, and glucuronidation. Whereas the activities of cytochrome P450-mediated monooxygenase and catechol-O-methyl transferase were very low and did not differ between the three cell lines, a pronounced difference was observed for UDP-glucuronosyl transferase activity, which was much higher in Hepa-1c1c4 than in c1c7 and c1c12 cells. In all three cell types, the rate of glucuronidation of AOH was about four times higher than that of AME. Whereas AME caused a concentration-dependent G2/M arrest in each cell line, AOH arrested Hepa-1c1c7 and c1c12 cells but not c1c4 cells. However, Hepa-1c1c4 cells were arrested by AOH when ?-glucuronidase was added to the incubation medium in order to reverse the formation of AOH glucuronides. We conclude that the failure of AOH to cause cell cycle inhibition in Hepa-1c1c4 cells is due to its efficient glucuronidation. The considerable UDP-glucuronosyl transferase activity of Hepa-1c1c4 cells should be taken into account when other compounds are studied in this cell line. Moreover, we demonstrate that differences in glucuronide formation between cell types can be overcome by the addition of ?-glucuronidase to the cell culture medium. PMID:22143556

Burkhardt, B; Jung, S A; Pfeiffer, E; Weiss, C; Metzler, M

2012-04-01

119

Glucuronidation of paracetamol by human liver microsomes in vitro / enzyme kinetic parameters and interactions with short-chain aliphatic alcohols and opiates.  

PubMed

In this study, glucuronidation of paracetamol (CAS 103-90-2) by human liver microsomes and the effects of aliphatic alcohols and opiates were investigated. Paracetamol glucuronidation was optimised for various incubation conditions. Ten different aliphatic alcohols and the opiates morphine, codeine and dihydrocodeine were analysed as inhibitors of paracetamol glucuronidation. Furthermore, the effects of paracetamol on morphine-3 and codeine glucuronidation were investigated. Enzyme kinetic analysis was carried out via determination of the parameters Km, Vmax, Ki and the type of inhibition. Except for methanol and ethanol, all Investigated alcohols inhibited glucuronidation of paracetamol. Ki values ranged between 4.59 mmol/l (n-pentanol) and 340.54 mmol/l (2-propanol). Extent of inhibition strongly depended on the structure and clearly increased with the length of the alkyl chain. All tested opiates inhibited paracetamol glucuronidation with Ki values between 4.02 mmol/l (dihydrocodeine) and 11.44 mmol/l (morphine). Paracetamol itself turned out to be an inhibitor of opiate glucuronidation. The apparent Ki values were 4.62 mmol/l (inhibition of morphine-3 glucuronidation) and 9.44 mmol/l (inhibition of codeine glucuronidation). A mixed inhibition type was determined for all substances. The in vitro studies show a great inhibition potential for the analysed substances. Transferring the results to the in vivo situation, a higher liver toxicity of paracetamol can be assumed, if concomitantly a lot of alcoholic beverages with congener alcohols--e.g. fruit schnapps or whisky--are drunk or if opiates--as analgesics or narcotics--are taken in higher doses. PMID:18380412

Boldt, Petra; Rothschild, Markus A; Kaeferstein, Herbert

2007-01-01

120

Identification of the Position of Mono-O-Glucuronide of Flavones and Flavonols by Analyzing Shift in Online UV Spectrum (?max) Generated from an Online Diode-arrayed Detector  

PubMed Central

The beneficial pharmacological effects of flavonoids such as chemo-prevention against cancer, aging and heart diseases are severely limited due to their extensive in vivo glucuronidation by UGTs. UGTs showed regiospecificity (i.e. position preference) in the glucuronidation of the flavonoids based on substrate’s chemical structure. In this paper, glucuronide(s) of 36 flavones and flavonols were generated using an in vitro glucuronidation reaction. UPLC/MS/MS was used to confirm the degree (mono- or di-) of glucuronidation in flavonoids with up to four hydroxyl group. UV spectra of flavonoids and their respective mono-O-glucuronides were generated using UPLC with an online diode-arrayed detector. Analysis of the extent of shift in spectra of glucuronides in Band I and Band II regions as reflected by changes in ?max value was used to identify the position of glucuronidation. The data showed that glucuronidation of 3- and 4’-hydroxyl resulted in Band I ?max hypsochromic shift (or blue shift) of 13–30 nm and 5–10 nm, respectively. And glucuronidation of 5-hydroxyl group caused Band II ?max hypsochromic shift of 5–10 nm. In contrast, glucuronidation of 7-hydroxyl group did not cause any ?max change in Band I or II ?max whereas glucuronidation of 6-hydroxyl group did not cause predictable changes in ?max values. The paper demonstrated for the first time that a rapid and robust analysis method using ?max changes in online UV spectra can be used to pinpoint region-specific glucuronidation of flavones and flavonols with hydroxyl groups at 4’, 3, 5, and/or 7 position(s). PMID:20687611

Singh, Rashim; Wu, Baojian; Tang, Lan; Liu, Zhongqiu; Hu, Ming

2012-01-01

121

The skin of the male African catfish, Clarias gariepinus: a source of steroid glucuronides.  

PubMed

Steroid metabolism in the skin of mature male African catfish, Clarias gariepinus, reared in the laboratory, was studied in vitro by tissue incubations with [3H]pregnenolone, [3H]dehydroepiandrosterone, [3H]17 alpha-hydroxyprogesterone, [3H]androstenedione, [14C]11 beta-hydroxyandrostenedione, and [3H]testosterone as precursors. While pregnenolone was not converted to any other steroid, dehydroepiandrosterone was transformed mainly to 5-androstene-3 beta, 17 beta-diol. The products of 17 alpha-hydroxyprogesterone incubations were 5 beta-pregnane-3 alpha,17 alpha-diol-20-one, 5 beta-pregnane-3 alpha,17 alpha, 20 beta-triol, and 5 beta-pregnan-17 alpha-o1-3,20-dione. The major steroids of androstenedione incubations were etiocholanolone, testosterone, and androsterone. Testosterone was converted mainly to etiocholanolone and androstenedione, and only small quantities of 11 beta-hydroxytestosterone, 11-ketotestosterone, and 11-ketoandrostenedione were the metabolites found in 11 beta-hydroxyandrostenedione incubation. These results demonstrated the presence of the enzymes 5 alpha- and 5 beta-reductases and 3 alpha-, 11 beta-, 17 beta-, and 20 beta-hydroxysteroid dehydrogenases in the skin. From enzymehistochemical results it appeared that the steroid conversions take place in the epithelial cells. Moreover, the presence of UDP-glucose dehydrogenase, an enzyme involved in the synthesis of glucuronic acid, in these cells indicates the possibility of steroid glucuronide formation. Indeed significant amounts of water-soluble steroid conjugates, particularly 5 beta-dihydrotestosterone- and testosterone-glucuronide, were found in the incubations with androstenedione and testosterone, indicating the presence of the UDP-glucuronosyl transferase in the catfish skin. In the light of these results, a role of the skin of African catfish in the production of semiochemicals having pheromonal properties is discussed. PMID:2956154

Ali, S A; Schoonen, W G; Lambert, J G; Van den Hurk, R; Van Oordt, P G

1987-06-01

122

Skin of the male African catfish, Clarias gariepinus: a source of steroid glucuronides  

SciTech Connect

Steroid metabolism in the skin of mature male African catfish, Clarias gariepinus, reared in the laboratory, was studied in vitro by tissue incubations with (/sup 3/H)pregnenolone, (/sup 3/H)dehydroepiandrosterone, (/sup 3/H)17 alpha-hydroxyprogesterone, (/sup 3/H)androstenedione, (/sup 14/C)11 beta-hydroxyandrostenedione, and (/sup 3/H)testosterone as precursors. While pregnenolone was not converted to any other steroid, dehydroepiandrosterone was transformed mainly to 5-androstene-3 beta, 17 beta-diol. The products of 17 alpha-hydroxyprogesterone incubations were 5 beta-pregnane-3 alpha,17 alpha-diol-20-one, 5 beta-pregnane-3 alpha,17 alpha, 20 beta-triol, and 5 beta-pregnan-17 alpha-o1-3,20-dione. The major steroids of androstenedione incubations were etiocholanolone, testosterone, and androsterone. Testosterone was converted mainly to etiocholanolone and androstenedione, and only small quantities of 11 beta-hydroxytestosterone, 11-ketotestosterone, and 11-ketoandrostenedione were the metabolites found in 11 beta-hydroxyandrostenedione incubation. These results demonstrated the presence of the enzymes 5 alpha- and 5 beta-reductases and 3 alpha-, 11 beta-, 17 beta-, and 20 beta-hydroxysteroid dehydrogenases in the skin. From enzymehistochemical results it appeared that the steroid conversions take place in the epithelial cells. Moreover, the presence of UDP-glucose dehydrogenase, an enzyme involved in the synthesis of glucuronic acid, in these cells indicates the possibility of steroid glucuronide formation. Indeed significant amounts of water-soluble steroid conjugates, particularly 5 beta-dihydrotestosterone- and testosterone-glucuronide, were found in the incubations with androstenedione and testosterone, indicating the presence of the UDP-glucuronosyl transferase in the catfish skin.

Ali, S.A.; Schoonen, W.G.; Lambert, J.G.; Van den Hurk, R.; Van Oordt, P.G.

1987-06-01

123

Manufacturing Ethyl Acetate From Fermentation Ethanol  

NASA Technical Reports Server (NTRS)

Conceptual process uses dilute product of fermentation instead of concentrated ethanol. Low-concentration ethanol, extracted by vacuum from fermentation tank, and acetic acid constitutes feedstock for catalytic reaction. Product of reaction goes through steps that increases ethyl acetate content to 93 percent by weight. To conserve energy, heat exchangers recycle waste heat to preheat process streams at various points.

Rohatgi, Naresh K.; Ingham, John D.

1991-01-01

124

Production of ethyl alcohol from bananas  

Microsoft Academic Search

The production of ethyl alcohol from waste bananas presents many special problems. During cooking, matting of the latex fibers from the banana peel recongeal when cooled and left untreated. This problem has been addressed by Alfaro by the use of CaC1â. Separation of solids prior to distillation of the mashes in an economical fashion and use of the by product

R. L. Jones; T. Towns

1983-01-01

125

40 CFR 180.429 - Chlorimuron ethyl; tolerances for residues.  

Code of Federal Regulations, 2011 CFR

...180.429 Chlorimuron ethyl; tolerances for residues. (a) General. Tolerances are established for residues of the herbicide chlorimuron ethyl, including its metabolites and degradates, in or on the commodities in the table below....

2011-07-01

126

Ethyl pyruvate improves survival in awake hemorrhage  

PubMed Central

Classical experimental models of hemorrhage are characterized by the use of anesthetics that may interfere with the typical immune responses and pathology of hemorrhage/resuscitation. Thus, therapeutic strategies successful in anesthetized animals might not be beneficial in clinical trials. In this study, we analyzed whether ethyl pyruvate could provide therapeutic benefits during resuscitation in awake (unanesthetized) hemorrhage. Our results indicate that hemorrhage in unanesthetized animals required approximately 25% higher blood withdrawal than anesthetized animals to achieve the same targeted mean arterial blood pressure. Resuscitation with Hextend reestablished circulatory volume and improved survival during resuscitation of awake rodents. Yet, over 75% of the animals resuscitated with Hextend died within the first hours after hemorrhage. Resuscitation with Hextend containing 50 mM ethyl pyruvate protected over 87% of the animals. This survival benefit did not correlate with significant changes in the metabolic markers but with an anti-inflammatory potential during resuscitation. Unlike classical hemorrhage in anesthetized animals, ethyl pyruvate reestablished mean arterial blood pressure significantly earlier than Hextend in unanesthetized rodents. Unanesthetized animals showed twofold higher serum tumor necrosis factor (TNF)-? than anesthetized animals subjected to the same blood pressure. This process was not due to the response of a single organ, but affected all the analyzed organs including the lung, heart, spleen, and liver. Although resuscitation with Hextend failed to attenuate systemic TNF-? levels, it inhibited TNF-? levels in the lung, heart, and liver but not in the spleen. Unlike Hextend, resuscitation with ethyl pyruvate prevented high serum TNF-? levels and blunted TNF-? responses in all the organs including the spleen. These studies indicate that the inflammatory responses in anesthetized animals differ from that in unanesthetized animals and that awake hemorrhage can provide advantages in the study of anti-inflammatory strategies during resuscitation. Ethyl pyruvate may attenuate systemic inflammatory responses during resuscitation and improve survival in experimental models of awake hemorrhage. PMID:19172241

Cai, Bolin; Brunner, Michael; Wang, Haichao; Wang, Ping; Deitch, Edwin A.

2011-01-01

127

40 CFR 180.430 - Fenoxaprop-ethyl; tolerances for residues.  

Code of Federal Regulations, 2010 CFR

...Tolerances are established for the combined residues of the herbicide fenoxaprop-ethyl [(±)-ethyl 2-[4-[(6-chloro-2-benzoxazolyl...Time-limited tolerances are established for combined residues of the herbicide fenoxaprop-ethyl, [(±)-ethyl...

2010-07-01

128

Interaction of hesperetin glucuronide conjugates with human BCRP, MRP2 and MRP3 as detected in membrane vesicles of overexpressing baculovirus-infected Sf9 cells  

Microsoft Academic Search

The citrus flavonoid hesperetin (4'-methoxy-3',5,7-trihydroxyflavanone) is the aglycone of hesperidin, the major flavonoid present in sweet oranges. Hesperetin 7-O-glucuronide (H7G) and hesperetin 3'-O-glucuronide (H3'G) are the two most abundant metabolites of hesperetin in vivo. In this study, their interaction with specific ABC transporters, believed to play a role in the disposition and bioavailability of hesperetin, was studied using Sf9 membranes

W. Brand; B. Oosterhuis; P. Krajcsi; D. Barron; F. Dionisi; Bladeren van P. J; I. Rietjens; G. Williamson

2011-01-01

129

Farnesol is glucuronidated in human liver, kidney and intestine in vitro, and is a novel substrate for UGT2B7 and UGT1A1  

PubMed Central

Farnesol is an isoprenoid found in many aromatic plants and is also produced in humans, where it acts on numerous nuclear receptors and has received considerable attention due to its apparent anticancer properties. Although farnesol has been studied for over 30 years, its metabolism has not been well characterized. Recently, farnesol was shown to be metabolized by cytochromes P450 in rabbit; however, neither farnesol hydroxylation nor glucuronidation in humans have been reported to date. In the present paper, we show for the first time that farnesol is metabolized to farnesyl glucuronide, hydroxyfarnesol and hydroxyfarnesyl glucuronide by human tissue microsomes, and we identify the specific human UGTs (uridine diphosphoglucuronosyltransferases) involved. Farnesol metabolism was examined by a sensitive LC (liquid chromatography)–MS/MS method. Results indicate that farnesol is a good substrate for glucuronidation in human liver, kidney and intestine microsomes (values in nmol/min per mg). Initial analysis using expressed human UGTs indicated that UGTs 1A1 and 2B7 were primarily responsible for glucuronidation in vitro, with significantly lower activity for all the other UGTs tested (UGTs 1A3, 1A4, 1A6, 1A9 and 2B4). Kinetic analysis and inhibition experiments indicate that, in liver microsomes, UGT1A1 is primarily responsible for farnesol glucuronidation; however, in intestine microsomes, UGT2B7 is probably the major isoform involved, with a very-low-micromolar Km. We also show the first direct evidence that farnesol can be metabolized to hydroxyfarnesol by human liver microsomes and that hydroxyfarnesol is metabolized further to hydroxyfarnesyl glucuronide. Thus glucuronidation may modulate the physiological and/or pharmacological properties of this potent signalling molecule. PMID:15320866

2004-01-01

130

Identification of Flavone Glucuronide Isomers by Metal Complexation and Tandem Mass Spectrometry: Regioselectivity of UDP-Glucuronosyltransferase Isozymes in the Biotransformation of Flavones  

PubMed Central

Flavone Glucuronide isomers of five flavones (chrysin, apigenin, luteolin, baicalein, and scutellarein) were differentiated by collision induced dissociation (CID) of [Co(II) (flavone-H) (4,7-diphenyl-1,10-phenanthroline)2]+ complexes. The complexes were generated via post-column addition of a metal/ligand solution after separation of the glucuronide products generated upon incubation of each flavone with an array of UDP-glucuronosyl-transferase (UGT) isozymes. Elucidation of the glucuronide isomers allowed a systematic investigation of the regioselectivity of twelve human UDP-glucuronosyl-transferase (UGT) isozymes, including eight UGT1A and four UGT2B isozymes. Glucuronidation of the 7-OH position was the preferred site for all the flavones except for luteolin, which possessed adjacent hydroxyl groups on the B ring. For all flavones and UGT isozymes, glucuronidation of the 5-OH position was never observed. As confirmed by the metal complexation/MS/MS strategy, glucuronidation of the 6-OH position only occurred for baicalein and scutellarein when incubated with three of the UGT isozymes. PMID:23362992

Robotham, Scott A.; Brodbelt, Jennifer S.

2013-01-01

131

Regioselectivity of human UDP-glucuronosyl-transferase 1A1 in the synthesis of flavonoid glucuronides determined by metal complexation and tandem mass spectrometry.  

PubMed

A three-part tandem mass spectrometric strategy that entails MSn analysis and a post-column LC-MS cobalt complexation method is developed to identify flavonoid monoglucuronide metabolites synthesized using the 1A1 isozyme of human UDP-glucuronosyltransferase (UGT). Ten flavonoid aglycons were used as substrates, spanning the subclasses of flavones, flavonols, and flavanones. The products were characterized by LC-MS and LC-MSn, with post-column cobalt complexation employed to pinpoint the specific sites of conjugation. The dissociation of complexes of the form [Co(II) (flavonoid glucuronide - H) (4,7-diphenyl-1,10-phenanthroline)(2)]+ allowed identification of the products and differentiation of isomers. The correlation between glycosylation site and elution order is used to provide additional structural confirmation. Flavonoids lacking a 3' hydroxyl group were glucuronidated only at position 7, while those containing this functionality also formed 3'-O-glucuronides and sometimes 4'-O-glucuronides, thus supporting the conclusion that the presence or absence of the 3'-OH group is the major determinant of the regioselectivity of glucuronidation. Moreover, the specific distribution of multiple glucuronide products (7-O, 3'-O, 4'-O) is governed by the subclass of flavonoid. PMID:18083528

Davis, Barry D; Brodbelt, Jennifer S

2008-02-01

132

Daidzein and genistein glucuronides in vitro are weakly estrogenic and activate human natural killer cells at nutritionally relevant concentrations.  

PubMed

Daidzein and genistein glucuronides (DG and GG), major isoflavone metabolites, may be partly responsible for biological effects of isoflavones, such as estrogen receptor binding and natural killer cell (NK) activation or inhibition. DG and GG were synthesized using 3-methylcholanthrene-induced rat liver microsomes. The Km and Vmax for daidzein and genistein were 9.0 and 7.7 micromol/L, and 0.7 and 1.6 micromol/(mg protein. min), respectively. The absence of ultraviolet absorbance maxima shifts in the presence of sodium acetate confirmed that the synthesized products were 7-O-glucuronides. DG and GG were further purified by a Sephadex LH-20 column. DG and GG competed with the binding of 17beta-(3H) estradiol to estrogen receptors of B6D2F1 mouse uterine cytosol. The concentrations required for 50% displacement of 17beta-(3H) estradiol (CB50) were: 17beta-estradiol, 1.34 nmol/L; diethylstilbestrol, 1.46 nmol/L; daidzein, 1.6 micromol/L; DG, 14.7 micromol/L; genistein, 0.154 micromol/L; GG, 7.27 micromol/L. In human peripheral blood NK cells, genistein at <0.5 micromol/L and DG and GG at 0.1-10 micromol/L enhanced NK cell-mediated K562 cancer cell killing significantly (P < 0.05). At > 0.5 micromol/L, genistein inhibited NK cytotoxicity significantly (P < 0.05). The glucuronides only inhibited NK cytotoxicity at 50 micromol/L. Isoflavones, and especially the isoflavone glucuronides, enhanced activation of NK cells by interleukin-2 (IL-2), additively. At physiological concentrations, DG and GG were weakly estrogenic, and they activated human NK cells in nutritionally relevant concentrations in vitro, probably at a site different from IL-2 action. PMID:10024618

Zhang, Y; Song, T T; Cunnick, J E; Murphy, P A; Hendrich, S

1999-02-01

133

Production of ethyl alcohol from bananas  

SciTech Connect

The production of ethyl alcohol from waste bananas presents many special problems. During cooking, matting of the latex fibers from the banana peel recongeal when cooled and left untreated. This problem has been addressed by Alfaro by the use of CaC1/sub 2/. Separation of solids prior to distillation of the mashes in an economical fashion and use of the by product are also of concern to banana processors.

Jones, R.L.; Towns, T.

1983-12-01

134

Isolation and characterization of a ?-glucuronide of hydroxylated SARM S1 produced using a combination of biotransformation and chemical oxidation.  

PubMed

In this study, using mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy, it has been confirmed that biotransformation with the fungus Cunninghamella elegans combined with chemical oxidation with the free radical tetramethylpiperidinyl-1-oxy (TEMPO) can produce drug glucuronides of ?-configuration. Glucuronic acid conjugates are a common type of metabolites formed by the human body. The detection of such conjugates in doping control and other kinds of forensic analysis would be beneficial owing to a decrease in analysis time as hydrolysis can be omitted. However the commercial availability of reference standards for drug glucuronides is poor. The selective androgen receptor modulator (SARM) SARM S1 was incubated with the fungus C. elegans. The sample was treated with the free radical TEMPO oxidizing agent and was thereafter purified by SPE. A glucuronic acid conjugate was isolated using a fraction collector connected to an ultra high performance liquid chromatographic (UHPLC) system. The isolated compound was characterized by NMR spectroscopy and mass spectrometry and its structure was confirmed as a glucuronic acid ?-conjugate of hydroxylated SARM S1 bearing the glucuronide moiety on carbon C-10. PMID:24879518

Rydevik, Axel; Lagojda, Andreas; Thevis, Mario; Bondesson, Ulf; Hedeland, Mikael

2014-09-01

135

Chemical and thermochemical aspects of the ozonolysis of ethyl oleate: decomposition enthalpy of ethyl oleate ozonide.  

PubMed

Neat ethyl oleate was ozonized in a bubble reactor and the progress of the ozonolysis was followed by infrared (FT-IR) spectroscopy and by the differential scanning calorimetry (DSC). The ozonolysis was conducted till a molar ratio O3/C=C?1 when the exothermal reaction spontaneously went to completion. A specific thermochemical calculation on ethyl oleate ozonation has been made to determine the theoretical heat of the ozonization reaction using the group increment approach. A linear relationship was found both in the integrated absorptivity of the ozonide infrared band at 1110 cm(-1) and the ozonolysis time as well as the thermal decomposition enthalpy of the ozonides and peroxides formed as a result of the ozonation. The DSC decomposition temperature of ozonated ethyl oleate occurs with an exothermal peak at about 150-155 °C with a decomposition enthalpy of 243.0 kJ/mol at molar ratio O3/C=C?1. It is shown that the decomposition enthalpy of ozonized ethyl oleate is a constant value (?243 kJ/mol) at any stage of the O3/C=C once an adequate normalization of the decomposition enthalpy for the amount of the adsorbed ozone is taken into consideration. The decomposition enthalpy of ozonized ethyl oleate was also calculated using a simplified thermochemical model, obtaining a result in reasonable agreement with the experimental value. PMID:23969233

Cataldo, Franco

2013-01-01

136

Determination of bilirubin glucuronide and assay of glucuronyltransferase with bilirubin as acceptor  

PubMed Central

1. Conjugated bilirubin is conveniently determined by coupling with the diazonium salt of ethyl anthranilate. 2. This method has been used in the development of assays for UDP-glucuronyltransferase (EC 2.4.1.17), with bilirubin as substrate, in rat liver homogenates, microsomal preparations and partly purified fractions. 3. Chromatographic analysis suggests that bilirubin monoglucuronide is the product of the enzyme systems studied. PMID:5660631

Van Roy, F. P.; Heirwegh, K. P. M.

1968-01-01

137

Stereoselective glucuronidation of ornidazole in humans: predominant contribution of UDP-glucuronosyltransferases 1A9 and 2B7.  

PubMed

Ornidazole [R,S-1-chloro-3-(2-methyl-5-nitro-1H-imidazol-1-yl)propan-2-ol] is a chiral 5-nitroimidazole class antimicrobial agent. This study aimed to investigate the principal metabolic pathway of ornidazole in humans and identify the major enzymes involved. A total of 19 metabolites were identified in human urine collected from patients with hepatobiliary diseases after an intravenous drip infusion of 500 mg of racemic ornidazole. Stereoselective glucuronidation, followed by renal excretion, was the principal metabolic pathway of ornidazole in humans, accounting for 37.3% of the administered dose. Screening assays with 12 available human recombinant UDP-glucuronosyltransferases (UGTs) demonstrated that UGT1A9 was the predominant UGT isoform involved in R-ornidazole glucuronidation, whereas S-ornidazole glucuronidation was almost exclusively catalyzed by UGT2B7. Chemical inhibition study with niflumic acid and flurbiprofen supported these findings. Enzyme kinetic parameters were then determined in human liver microsomes (HLMs), human kidney microsomes (HKMs), UGT1A9, and 2B7. The K(m) values for UGT1A9 (15.6 ± 1.6 mM for R-ornidazole) and 2B7 (3.8 ± 0.9 mM for S-ornidazole) were quite similar to those determined in HLMs and HKMs (20.1 ± 1.4 and 17.7 ± 4.0 mM for R-ornidazole; 6.6 ± 1.3 and 3.2 ± 0.4 mM for S-ornidazole). The in vitro intrinsic clearance (CL(int)) ratios of S- to R-ornidazole were approximately 4.3 in HLMs and 6.5 in HKMs, respectively. The hepatic and renal clearances were estimated based on the well-stirred model. Overall, stereoselective glucuronidation was the principal metabolic pathway of ornidazole in humans. Furthermore, UGT1A9 and 2B7 were the predominant UGT isoforms responsible for R- and S-ornidazole glucuronidation in humans, respectively. PMID:23571427

Du, Jiangbo; You, Tiangeng; Chen, Xiaoyan; Zhong, Dafang

2013-07-01

138

Identification of brain-targeted bioactive dietary quercetin-3-O-glucuronide as a novel intervention for Alzheimer's disease  

PubMed Central

Epidemiological and preclinical studies indicate that polyphenol intake from moderate consumption of red wines may lower the relative risk for developing Alzheimer's disease (AD) dementia. There is limited information regarding the specific biological activities and cellular and molecular mechanisms by which wine polyphenolic components might modulate AD. We assessed accumulations of polyphenols in the rat brain following oral dosage with a Cabernet Sauvignon red wine and tested brain-targeted polyphenols for potential beneficial AD disease-modifying activities. We identified accumulations of select polyphenolic metabolites in the brain. We demonstrated that, in comparison to vehicle-control treatment, one of the brain-targeted polyphenol metabolites, quercetin-3-O-glucuronide, significantly reduced the generation of ?-amyloid (A?) peptides by primary neuron cultures generated from the Tg2576 AD mouse model. Another brain-targeted metabolite, malvidin-3-O-glucoside, had no detectable effect on A? generation. Moreover, in an in vitro analysis using the photo-induced cross-linking of unmodified proteins (PICUP) technique, we found that quercetin-3-O-glucuronide is also capable of interfering with the initial protein-protein interaction of A?1–40 and A?1–42 that is necessary for the formation of neurotoxic oligomeric A? species. Lastly, we found that quercetin-3-O-glucuronide treatment, compared to vehicle-control treatment, significantly improved AD-type deficits in hippocampal formation basal synaptic transmission and long-term potentiation, possibly through mechanisms involving the activation of the c-Jun N-terminal kinases and the mitogen-activated protein kinase signaling pathways. Brain-targeted quercetin-3-O-glucuronide may simultaneously modulate multiple independent AD disease-modifying mechanisms and, as such, may contribute to the benefits of dietary supplementation with red wines as an effective intervention for AD.—Ho, L., Ferruzzi, M. G., Janle, E. M., Wang, J., Gong, B., Chen, T.-Y., Lobo, J., Cooper, B., Wu, Q. L., Talcott, S. T., Percival, S. S., Simon, J. E., Pasinetti, G. M. Identification of brain-targeted bioactive dietary quercetin-3-O-glucuronide as a novel intervention for Alzheimer's disease. PMID:23097297

Ho, Lap; Ferruzzi, Mario G.; Janle, Elsa M.; Wang, Jun; Gong, Bing; Chen, Tzu-Ying; Lobo, Jessica; Cooper, Bruce; Wu, Qing Li; Talcott, Stephen T.; Percival, Susan S.; Simon, James E.; Pasinetti, Giulio Maria

2013-01-01

139

Regulation of endobiotics glucuronidation by ligand-activated transcription factors: physiological function and therapeutic potential.  

PubMed

Recent progresses in molecular pharmacology approaches have allowed the identification and characterization of a series of nuclear receptors (NR) which efficiently control the level UDP-glucuronosyltransferase (UGT) genes expression. These regulatory processes ensure optimized UGT expression in response to specific endogenous and/or exogenous stimuli. Interestingly, numerous endogenous activators of these NRs are conjugated by the UGT enzymes they regulate. In such a case, the NR-dependent regulation of UGT genes corresponds to a feedforward/feedback mechanism by which a bioactive molecule controls its own concentrations. In the present review, we will discuss i) how bilirubin reduces its circulating levels by activating AhR in the liver; ii) how bile acids modulate their hepatic glucuronidation via PXR- and FXR-dependent processes in enterohepatic tissues; and iii) how androgens inhibit their cellular metabolism in prostate cancer cells through an AR-dependent mechanism. Subsequently, with further discussion of the same examples (bilirubin and bile acids), we will illustrate how NR-dependent regulation of UGT enzymes may contribute to the beneficial effects of pharmacological activators of nuclear receptors, such as CAR and PPARa. PMID:19831728

Verreault, Mélanie; Kaeding, Jenny; Caron, Patrick; Trottier, Jocelyn; Grosse, Laurent; Houssin, Elise; Pâquet, Sophie; Perreault, Martin; Barbier, Olivier

2010-02-01

140

Quantitative Determination of Common Urinary Odorants and Their Glucuronide Conjugates in Human Urine  

PubMed Central

Our previous study on the identification of common odorants and their conjugates in human urine demonstrated that this substance fraction is a little-understood but nonetheless a promising medium for analysis and diagnostics in this easily accessible physiological medium. Smell as an indicator for diseases, or volatile excretion in the course of dietary processes bares high potential for a series of physiological insights. Still, little is known today about the quantitative composition of odorous or volatile targets, as well as their non-volatile conjugates, both with regard to their common occurrence in urine of healthy subjects, as well as in that of individuals suffering from diseases or other physiological misbalancing. Accordingly, the aim of our study was to develop a highly sensitive and selective approach to determine the common quantitative composition of selected odorant markers in healthy human subjects, as well as their corresponding glucuronide conjugates. We used one- and two-dimensional high resolution gas chromatography-mass spectrometry in combination with stable isotope dilution assays to quantify commonly occurring and potent odorants in human urine. The studies were carried out on both native urine and on urine that had been treated by glucuronidase assays, with analysis of the liberated odor-active compounds using the same techniques. Analytical data are discussed with regard to their potential translation as future diagnostic tool. PMID:24958143

Wagenstaller, Maria; Buettner, Andrea

2013-01-01

141

Quercetin-3-O-glucuronide induces ABCA1 expression by LXR? activation in murine macrophages  

SciTech Connect

Highlights: •The major circulating quercetin metabolite (Q3GA) activated LXR?. •Q3GA induced ABCA1 via LXR? activation in macrophages. •Nelumbo nucifera leaf extracts contained quercetin glycosides. •N. nucifera leaf extract feeding elevated HDLC in mice. -- Abstract: Reverse cholesterol transport (RCT) removes excess cholesterol from macrophages to prevent atherosclerosis. ATP-binding cassette, subfamily A, member 1 (ABCA1) is a crucial cholesterol transporter involved in RCT to produce high density lipoprotein-cholesterol (HDLC), and is transcriptionally regulated by liver X receptor alpha (LXR?), a nuclear receptor. Quercetin is a widely distributed flavonoid in edible plants which prevented atherosclerosis in an animal model. We found that quercetin-3-O-glucuronide (Q3GA), a major quercetin metabolite after absorption from the digestive tract, enhanced ABCA1 expression, in vitro, via LXR? in macrophages. In addition, leaf extracts of a traditional Asian edible plant, Nelumbo nucifera (NNE), which contained abundant amounts of quercetin glycosides, significantly elevated plasma HDLC in mice. We are the first to present experimental evidence that Q3GA induced ABCA1 in macrophages, and to provide an alternative explanation to previous studies on arteriosclerosis prevention by quercetin.

Ohara, Kazuaki, E-mail: Kazuaki_Ohara@kirin.co.jp [Research Laboratories for Health Science and Food Technologies, Kirin Company Limited, 1-13-5 Fukuura, Kanazawa-ku, Yokohama 236-0004 (Japan)] [Research Laboratories for Health Science and Food Technologies, Kirin Company Limited, 1-13-5 Fukuura, Kanazawa-ku, Yokohama 236-0004 (Japan); Wakabayashi, Hideyuki [Laboratory for New Product Development, Kirin Beverage Company Limited, 1-17-1 Namamugi, Tsurumi-ku, Yokohama 230-8628 (Japan)] [Laboratory for New Product Development, Kirin Beverage Company Limited, 1-17-1 Namamugi, Tsurumi-ku, Yokohama 230-8628 (Japan); Taniguchi, Yoshimasa [Research Laboratories for Health Science and Food Technologies, Kirin Company Limited, 1-13-5 Fukuura, Kanazawa-ku, Yokohama 236-0004 (Japan)] [Research Laboratories for Health Science and Food Technologies, Kirin Company Limited, 1-13-5 Fukuura, Kanazawa-ku, Yokohama 236-0004 (Japan); Shindo, Kazutoshi [Department of Food and Nutrition, Japan Women’s University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo 112-8681 (Japan)] [Department of Food and Nutrition, Japan Women’s University, 2-8-1 Mejirodai, Bunkyo-ku, Tokyo 112-8681 (Japan); Yajima, Hiroaki [Research Laboratories for Health Science and Food Technologies, Kirin Company Limited, 1-13-5 Fukuura, Kanazawa-ku, Yokohama 236-0004 (Japan)] [Research Laboratories for Health Science and Food Technologies, Kirin Company Limited, 1-13-5 Fukuura, Kanazawa-ku, Yokohama 236-0004 (Japan); Yoshida, Aruto [Central Laboratories for Key Technologies, Kirin Company Limited, 1-13-5 Fukuura, Kanazawa-ku, Yokohama 236-0004 (Japan)] [Central Laboratories for Key Technologies, Kirin Company Limited, 1-13-5 Fukuura, Kanazawa-ku, Yokohama 236-0004 (Japan)

2013-11-29

142

Sensitive determination of estriol-16-glucuronide using surface plasmon resonance sensing.  

PubMed

For the quantitative evaluation of low levels of an estriol metabolite of estriol (estriol-16-glucuronide (E3-16G)) in liquid media, we developed a simple and highly sensitive immunoassay using a surface plasmon resonance (SPR) biosensor which did not require any time-consuming sample pretreatment steps. E3-16G was conjugated to ovalbumin (OVA) through an oligoethylene glycol (OEG) linker to form protein conjugates (E3-16G-OEG-OVA), which were then immobilized on a carboxymethyl dextran-coated sensor chip via amine coupling to develop inhibition immunoassays. A limit of detection (LOD) of 76 pg/mL was achieved using a rabbit anti-sheep primary antibody as a binding agent. The detection limit was further improved by using synthesized gold colloids (15 nm) as high mass labels conjugated to the primary antibody. In this Au nanoparticle-enhanced assay, the concentration of E3-16G in aqueous samples could be determined in 7.5 min at a level as low as 14 pg/mL. In addition, the high stability of the E3-16G-OEG-OVA surface gave no obvious drop in antibody-binding capability after more than 1000 binding/regeneration cycles which significantly lowered the research cost. PMID:19465041

Jiang, Xiuqian; Waterland, Mark; Blackwell, Len; Wu, Yinqiu; Jayasundera, Krishanthi P; Partridge, Ashton

2009-10-01

143

Phase II Metabolism in Human Skin: Skin Explants Show Full Coverage for Glucuronidation, Sulfation, N-Acetylation, Catechol Methylation, and Glutathione Conjugation.  

PubMed

Although skin is the largest organ of the human body, cutaneous drug metabolism is often overlooked, and existing experimental models are insufficiently validated. This proof-of-concept study investigated phase II biotransformation of 11 test substrates in fresh full-thickness human skin explants, a model containing all skin cell types. Results show that skin explants have significant capacity for glucuronidation, sulfation, N-acetylation, catechol methylation, and glutathione conjugation. Novel skin metabolites were identified, including acyl glucuronides of indomethacin and diclofenac, glucuronides of 17?-estradiol, N-acetylprocainamide, and methoxy derivatives of 4-nitrocatechol and 2,3-dihydroxynaphthalene. Measured activities for 10 ?M substrate incubations spanned a 1000-fold: from the highest 4.758 pmol·mg skin(-1)·h(-1) for p-toluidine N-acetylation to the lowest 0.006 pmol·mg skin(-1)·h(-1) for 17?-estradiol 17-glucuronidation. Interindividual variability was 1.4- to 13.0-fold, the highest being 4-methylumbelliferone and diclofenac glucuronidation. Reaction rates were generally linear up to 4 hours, although 24-hour incubations enabled detection of metabolites in trace amounts. All reactions were unaffected by the inclusion of cosubstrates, and freezing of the fresh skin led to loss of glucuronidation activity. The predicted whole-skin intrinsic metabolic clearances were significantly lower compared with corresponding whole-liver intrinsic clearances, suggesting a relatively limited contribution of the skin to the body's total systemic phase II enzyme-mediated metabolic clearance. Nevertheless, the fresh full-thickness skin explants represent a suitable model to study cutaneous phase II metabolism not only in drug elimination but also in toxicity, as formation of acyl glucuronides and sulfate conjugates could play a role in skin adverse reactions. PMID:25339109

Manevski, Nenad; Swart, Piet; Balavenkatraman, Kamal Kumar; Bertschi, Barbara; Camenisch, Gian; Kretz, Olivier; Schiller, Hilmar; Walles, Markus; Ling, Barbara; Wettstein, Reto; Schaefer, Dirk J; Itin, Peter; Ashton-Chess, Joanna; Pognan, Francois; Wolf, Armin; Litherland, Karine

2015-01-01

144

Optimization of ethyl ester production assisted by ultrasonic irradiation.  

PubMed

This study presents the optimization of the continuous flow potassium hydroxide-catalyzed synthesis of ethyl ester from palm oil with ultrasonic assistance. The process was optimized by application of factorial design and response surface methodology. The independent variables considered were ethanol to oil molar ratio, catalyst concentration, reaction temperature and ultrasonic amplitude; and the response was ethyl ester yield. The results show that ethanol to oil molar ratio, catalyst concentration, and ultrasonic amplitude have positive effect on ethyl ester yield, whereas reaction temperature has negative influence on ethyl ester yield. Second-order models were developed to predict the responses analyzed as a function of these three variables, and the developed models predicts the results in the experimental ranges studied adequately. This study shows that ultrasonic irradiation improved the ethyl ester production process to achieve ethyl ester yields above 92%. PMID:25116594

Noipin, K; Kumar, S

2015-01-01

145

Disruption of thyroid hormone homeostasis in Ugt1a-deficient Gunn rats by microsomal enzyme inducers is not due to enhanced thyroxine glucuronidation  

SciTech Connect

Microsomal enzyme inducers (MEI) that increase UDP-glucuronosyltransferases (UGTs) are thought to increase glucuronidation of thyroxine (T{sub 4}), thus reducing serum T{sub 4}, and subsequently increasing thyroid stimulating hormone (TSH). Ugt1a1 and Ugt1a6 mediate T{sub 4} glucuronidation. Therefore, this experiment determined the involvement of Ugt1a enzymes in increased T{sub 4} glucuronidation, decreased serum T{sub 4}, and increased TSH after MEI treatment. Male Wistar and Ugt1a-deficient Wistar (Gunn) rats were fed a control diet or diet containing pregnenolone-16{alpha}-carbonitrile (PCN; 800 ppm), 3-methylcholanthrene (3-MC; 200 ppm), or Aroclor 1254 (PCB; 100 ppm) for 7 days. Serum T{sub 4}, triiodothyronine (T{sub 3}), and TSH concentrations, hepatic T{sub 4}/T{sub 3} glucuronidation, and thyroid histology and follicular cell proliferation were investigated. PCN, 3-MC, and PCB treatments decreased serum T{sub 4}, whereas serum T{sub 3} was maintained in both Gunn and Wistar rats (except for PCB treatment). TSH was increased in Wistar and Gunn rats after PCN (130 and 277%) or PCB treatment (72 and 60%). T{sub 4} glucuronidation in Wistar rats was increased after PCN (298%), 3-MC (85%), and PCB (450%), but was extremely low in Gunn rats, and unchanged after MEI. T{sub 3} glucuronidation was increased after PCN (121%) or PCB (58%) in Wistar rats, but only PCN increased T{sub 3} glucuronidation in Gunn rats (43%). PCN treatment induced thyroid morphological changes and increased follicular cell proliferation in both strains. These data demonstrate that T{sub 4} glucuronidation cannot be increased in Ugt1a-deficient Gunn rats. Thus, the decrease in serum T{sub 4}, increase in TSH, and increase in thyroid cell proliferation after MEI are not dependent on increased T{sub 4} glucuronidation, and cannot be attributed to Ugt1a enzymes.

Richardson, Terrilyn A.; Klaassen, Curtis D., E-mail: cklaasse@kumc.ed

2010-10-01

146

Hydroxycinnamic acid ethyl esters as precursors to ethylphenols in wine.  

PubMed

A method for determining ethyl coumarate and ethyl ferulate in wine using GC-MS with deuterium-labeled analogues has been developed and used to measure the evolution of these two esters during the production of two commercial monovarietal red wines, cv. Grenache and Shiraz. During fermentation, the concentration of ethyl coumarate rose from low levels to 0.4 mg/L in Grenache and 1.6 mg/L in Shiraz wines. These concentrations then increased further during barrel aging to 1.4 and 3.6 mg/L, respectively. The concentration of ethyl ferulate was much lower, reaching a maximum of only 0.09 mg/L. Conversion of ethyl coumarate and ethyl ferulate to their corresponding ethylphenols was observed during fermentations of a synthetic medium with two strains of Dekkera bruxellensis (AWRI 1499 and AWRI 1608), while a third (strain AWRI 1613) produced no ethylphenols at all from these precursors. Strains AWRI 1499 and 1608 produced 4-ethylphenol from ethyl coumarate in 68% and 57% yields, respectively. The corresponding yields of 4-ethylguaiacol from ethyl ferulate were much lower, 7% and 3%. Monitoring of ethyl coumarate and ethyl ferulate concentration during the Dekkera fermentations showed that the selectivity for ethylphenol production according to yeast strain and the precursor was principally a result of variation in esterase activity. Consequently, ethyl coumarate can be considered to be a significant precursor to 4-ethylphenol in wines affected by these two strains of Brettanomyces/Dekkera yeast, while ethyl ferulate is not an important precursor to 4-ethylguaiacol. PMID:22324721

Hixson, Josh L; Sleep, Nicola R; Capone, Dimitra L; Elsey, Gordon M; Curtin, Christopher D; Sefton, Mark A; Taylor, Dennis K

2012-03-01

147

Glucuronidation Converts Clopidogrel to a Strong Time-Dependent Inhibitor of CYP2C8: A Phase II Metabolite as a Perpetrator of Drug-Drug Interactions.  

PubMed

Cerivastatin and repaglinide are substrates of cytochrome P450 (CYP)2C8, CYP3A4, and organic anion-transporting polypeptide (OATP)1B1. A recent study revealed an increased risk of rhabdomyolysis in patients using cerivastatin with clopidogrel, warranting further studies on clopidogrel interactions. In healthy volunteers, repaglinide area under the concentration-time curve (AUC0-?) was increased 5.1-fold by a 300-mg loading dose of clopidogrel and 3.9-fold by continued administration of 75?mg clopidogrel daily. In vitro, we identified clopidogrel acyl-?-D-glucuronide as a potent time-dependent inhibitor of CYP2C8. A physiologically based pharmacokinetic model indicated that inactivation of CYP2C8 by clopidogrel acyl-?-D-glucuronide leads to uninterrupted 60-85% inhibition of CYP2C8 during daily clopidogrel treatment. Computational modeling resulted in docking of clopidogrel acyl-?-D-glucuronide at the CYP2C8 active site with its thiophene moiety close to heme. The results indicate that clopidogrel is a strong CYP2C8 inhibitor via its acyl-?-D-glucuronide and imply that glucuronide metabolites should be considered potential inhibitors of CYP enzymes. PMID:24971633

Tornio, A; Filppula, A M; Kailari, O; Neuvonen, M; Nyrönen, T H; Tapaninen, T; Neuvonen, P J; Niemi, M; Backman, J T

2014-10-01

148

Signal enhancement of glucuronide conjugates in LC-MS/MS by derivatization with the phosphonium propylamine cation tris(trimethoxyphenyl) phosphonium propylamine, for forensic purposes.  

PubMed

Although chemical derivatization for signal enhancement in drug testing is most often associated with gas chromatography, it also has the potential to improve the detection of analytes poorly ionized by atmospheric pressure ionization techniques, such as electrospray ionization used in liquid chromatography-mass spectrometry. A number of acidic compounds, namely drug glucuronides (e.g. conjugates of temazepam, oxazepam, lorazepam, morphine, testosterone, epitestosterone, 5-?-dihydrotestosterone, androsterone, p-nitrophenol, and paracetamol) were successfully derivatized with tris(trimethoxyphenyl) phosphoniumpropylamine to introduce a quaternary cation functionality to the analytes. Benzodiazepine glucuronides were more specifically investigated, and following positive mode electrospray ionization mass spectrometry, average improvements to peak areas as a result of derivatization were 67-, 6-, and 7- fold for temazepam, oxazepam, and lorazepam glucuronides. Average improvements to the signal-to-noise ratios for temazepam, oxazepam, and lorazepam glucuronides were 1336-, 371- and 217-fold, respectively. The values obtained for the derivatized conjugate were also typically higher than those for the underivatized parent drug. Urine containing benzodiazepine glucuronides was also successfully derivatized. The data indicates potential for the use of charge derivatization to improve the detection of molecules with acidic functionalities by liquid chromatography-mass spectrometry (LC-MS) techniques in certain scenarios. PMID:24753456

Turfus, Sophie C; Halket, John M; Parkin, Mark C; Cowan, David A; Braithwaite, Robin A; Kicman, Andrew T

2014-05-01

149

KEY COMPARISON: Final report on CCQM-K69 key comparison: Testosterone glucuronide in human urine  

NASA Astrophysics Data System (ADS)

The CCQM-K69 key comparison of testosterone glucuronide in human urine was organized under the auspices of the CCQM Organic Analysis Working Group (OAWG). The National Measurement Institute Australia (NMIA) acted as the coordinating laboratory for the comparison. The samples distributed for the key comparison were prepared at NMIA with funding from the World Anti-Doping Agency (WADA). WADA granted the approval for this material to be used for the intercomparison provided the distribution and handling of the material were strictly controlled. Three national metrology institutes (NMIs)/designated institutes (DIs) developed reference methods and submitted data for the key comparison along with two other laboratories who participated in the parallel pilot study. A good selection of analytical methods and sample workup procedures was displayed in the results submitted considering the complexities of the matrix involved. The comparability of measurement results was successfully demonstrated by the participating NMIs. Only the key comparison data were used to estimate the key comparison reference value (KCRV), using the arithmetic mean approach. The reported expanded uncertainties for results ranged from 3.7% to 6.7% at the 95% level of confidence and all results agreed within the expanded uncertainty of the KCRV. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Liu, Fong-Ha; Mackay, Lindsey; Murby, John

2010-01-01

150

Investigation on possible transformations of cortisol, cortisone and cortisol glucuronide in bovine faecal matter using liquid chromatography-mass spectrometry.  

PubMed

Given the close resemblance of the ring A structure of prednisolone and prednisone on the one hand, and of androstadienedione on the other, the transformation of cortisol and cortisone into prednisolone and prednisone in cattle faeces was evaluated. A simple method that does not involve extraction but only the 1:100 dilution of cattle faeces, spiking with 400ng/mL cortisol, cortisone or cortisol glucuronide and incubation of the suspension, was used. The analyses were performed by HPLC-MS(3) to detect the supposed Delta(1) dehydrogenation of the glucocorticoids. The decision limits (CCalpha) and detection capabilities (CCbeta) were 2.0 and 3.0ng/mL for cortisol, cortisone and prednisolone, 3.0 and 4.0ng/mL for cortisol glucuronide and 7.0 and 10.0ng/mL for prednisone, respectively. Intra-day and inter-day coefficients of variation (CV%), were 5.6-6.2 and 5.2-6.6 for cortisol glucuronide, cortisol, cortisone and prednisolone, and 16.0 and 16.2 for prednisone, respectively. The recoveries were in the range 110-143% for all analytes. Regression coefficients (R2) were in the range 0.996-0.999 for all analytes. The results show the hydrolysis of the conjugated form and the dehydrogenation in ring A in diluted faeces. It is therefore predicted that urine contaminated with faeces may be positive for prednisone and prednisolone in the same way as they are positive for boldenone, i.e. as a result of microbiological dehydrogenase activity on cortisol and cortisone. PMID:20116390

Arioli, Francesco; Fidani, Marco; Casati, Alessio; Fracchiolla, Maria L; Pompa, Giuseppe

2010-04-01

151

Determination of sulfates and glucuronides of endogenic steroids in biofluids by high-performance liquid chromatography/orbitrap mass spectrometry  

NASA Astrophysics Data System (ADS)

the possibility of selective determination of testosterone and epitestosterone glucuronides in urine by high-performance liquid chromatography/high-resolution mass spectrometry using solid phase microextraction on a meps cartridge was studied. the effect of the biological matrix on the spectra of conjugated steroids can be taken into account by using the spectra of conjugates recorded for urine samples after hydrolysis as reference spectra. the conditions of fragmentation in the ion source were optimized for separate analytes. this method was used for analyzing real samples with different testosterone/epitestosterone ratios. variations in conjugate contents and qualitative changes in the steroid profile of endogenic compounds were observed.

Semenistaya, E. N.; Virus, E. D.; Rodchenkov, G. M.

2009-04-01

152

Determination of 125I-labelled thyroxine glucuronide by reversed-phase high-performance liquid chromatography using on-line radiochemical detection to determine UDPglucuronosyltransferase activity.  

PubMed

A convenient, fast and highly sensitive high-performance liquid chromatographic method, using on-line radiochemical detection, is described for the determination of [125I]thyroxine glucuronide. The method involves direct injection of the supernatant, a total analysis time of 30 min and a detection limit of 1 pmol. The results demonstrate that the method is suitable for the determination of UDPglucuronosyltransferase activity with thyroxine as substrate in native hepatic microsomes. The rate of thyroxine glucuronidation in microsomes from rats treated with Arodor 1254 was ten times higher than in control microsomes, indicating that with this method, increases of UDPglucuronosyltransferase thyroxine activities, often associated with hepatic induction process involved in thyroid hypertrophy, can be easily detected. This method could also be applied to all experimental biological systems that involve the separation and quantification of [125I]thyroxine and [125I]thyroxine glucuronide. PMID:1939453

Ducrotoy, G; Richert, L; De Sandro, V; Lurier, D; Pacaud, E

1991-05-31

153

IRIS TOXICOLOGICAL REVIEW OF METHYL ETHYL KETONE (2003 Final)  

EPA Science Inventory

EPA is announcing the release of the final report, "Toxicological Review of Methyl Ethyl Ketone: in support of the Integrated Risk Information System (IRIS)". The updated Summary for Methyl Ethyl Ketone and accompanying Quickview have also been added to the IRIS Database. ...

154

A morphogenetic regulatory role for ethyl alcohol in Candida albicans.  

PubMed

Regulation of morphogenesis through the production of chemical signalling molecules such as isoamyl alcohol, 2-phenylethyl alcohol, 1-dodecanol, E-nerolidol and farnesol is reported in Candida albicans. The present study focuses on the effect of ethyl alcohol on C. albicans dimorphism and biofilm development. Ethyl alcohol inhibited germ tube formation induced by the four standard inducers in a concentration-dependent manner. The germ tube inhibitory concentration (4%) did not have any effect on the growth and viability of C. albicans cells. Ethyl alcohol also inhibited the elongation of germ tubes. Four percentage of ethyl alcohol significantly inhibited biofilm development on polystyrene and silicone surfaces. We suggest a potential morphogenetic regulatory role for ethyl alcohol, which may influence dissemination, virulence and establishment of infection. PMID:21605190

Chauhan, Nitin M; Raut, Jayant S; Karuppayil, S Mohan

2011-11-01

155

19 CFR 10.99 - Importation of ethyl alcohol for nonbeverage purposes.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false Importation of ethyl alcohol for nonbeverage purposes. 10.99 Section...REDUCED RATE, ETC. General Provisions Ethyl Alcohol § 10.99 Importation of ethyl alcohol for nonbeverage purposes. (a)...

2012-04-01

156

19 CFR 10.99 - Importation of ethyl alcohol for nonbeverage purposes.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false Importation of ethyl alcohol for nonbeverage purposes. 10.99 Section...REDUCED RATE, ETC. General Provisions Ethyl Alcohol § 10.99 Importation of ethyl alcohol for nonbeverage purposes. (a)...

2011-04-01

157

19 CFR 10.99 - Importation of ethyl alcohol for nonbeverage purposes.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Importation of ethyl alcohol for nonbeverage purposes. 10.99 Section...REDUCED RATE, ETC. General Provisions Ethyl Alcohol § 10.99 Importation of ethyl alcohol for nonbeverage purposes. (a)...

2013-04-01

158

19 CFR 10.99 - Importation of ethyl alcohol for nonbeverage purposes.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Importation of ethyl alcohol for nonbeverage purposes. 10.99 Section...REDUCED RATE, ETC. General Provisions Ethyl Alcohol § 10.99 Importation of ethyl alcohol for nonbeverage purposes. (a)...

2010-04-01

159

19 CFR 10.99 - Importation of ethyl alcohol for nonbeverage purposes.  

...2014-04-01 false Importation of ethyl alcohol for nonbeverage purposes. 10.99 Section...REDUCED RATE, ETC. General Provisions Ethyl Alcohol § 10.99 Importation of ethyl alcohol for nonbeverage purposes. (a)...

2014-04-01

160

Determination of free and glucuronidated kaempferol in rat plasma by LC-MS/MS: application to pharmacokinetic study.  

PubMed

Flavanoid kaempferol is mainly present as glucuronides and sulfates in rat plasma, and small amounts of the intact aglycone are also detected. In the this study, a rapid, specific and sensitive liquid chromatography-electrospray ionization-tandem mass spectrometry method (HPLC-MS/MS) was developed and validated for determination of kaempferol and its major metabolite glucuronidated kaempferol in rat plasma. A liquid-liquid extraction with acetic ether was involved for the extraction of kaempferol and internal standard. Analytes were separated on a C18 column (150 mm x 2.1 mm, 4.5 microm, Waters Corp.) with isocratic elution at a flow-rate of 0.3 ml min(-1). The mobile phase was consisted of 0.5% formic acid and acetonitrile (50:50, v/v). The Quattro Premier HPLC-MS/MS was operated under the multiple reaction-monitoring mode (MRM) using the electrospray ionization technique. The method was validated according to the FDA guidelines for validation of bioanalytical method. The validated method was successfully applied to the study of the pharmacokinetics in rats after oral administration of kaempferol with different doses. PMID:20591752

Zhang, Wei-Dong; Wang, Xiao-Juan; Zhou, Si-Yuan; Gu, Yi; Wang, Rong; Zhang, Tao-Li; Gan, Hong-Quan

2010-08-01

161

Biodegradation of pyrazosulfuron-ethyl by Acinetobacter sp. CW17.  

PubMed

The pyrazosulfuron-ethyl-degrading bacterium, designated as CW17, was isolated from contaminated soil near the warehouse of the factory producing pyrazosulfuron-ethyl in Changsha city, China. The strain CW17 was identified as Acinetobacter sp. based on analyses of 94 carbon source utilization or chemical sensitivity in Biolog microplates, conventional phenotypic characteristics, and 16S rRNA gene sequencing. When pyrazosulfuron-ethyl was provided as the sole carbon source, the effects of pyrazosulfuron-ethyl concentration, pH, and temperature on biodegradation were examined. The degradation rates of pyrazosulfuron-ethyl at initial concentrations of 5.0, 20.0, and 50.0 mg/L were 48.0%, 77.0%, and 32.6%, respectively, after inoculation for 7 days. The growth of the strain was inhibited at low pH buffers. The chemical degradation occurs much faster at low pH than at neutral and basic pH conditions. The degradation rate of pyrazosulfuron-ethyl at 30°C was faster than those at 20 and 37°C by CW17 strains. Two metabolites of degradation were analyzed by liquid chromatography-mass spectroscopy (LC/MS). Based on the identified products, strain CW17 seemed to be able to degrade pyrazosulfuron-ethyl by cleavage of the sulfonylurea bridge. PMID:22388979

Wang, Yanhui; Du, Liangwei; Chen, Yingxi; Liu, Xiaoliang; Zhou, Xiaomao; Tan, Huihua; Bai, Lianyang; Zeng, Dongqiang

2012-03-01

162

The covalent immobilization of microsomal uridine diphospho-glucuronosyltransferase (UDPGT): initial synthesis and characterization of an UDPGT immobilized enzyme reactor for the on-line study of glucuronidation.  

PubMed

The microsomal fraction of rat liver containing uridine diphospho-glucuronosyltransferase (UDPGT; EC 2.4.1.17) has been covalently immobilized on a high performance chromatographic support. In this study Nucleosil Si-500 silica was converted into diol-bonded silica and subsequently converted into an aldehyde form through oxidation with sodium periodate. The microsomal fraction was immobilized via Schiff base formation followed by reduction with sodium cyanoborohydride. The resulting immobilized enzyme reactor (IMER) was placed in a multi-dimensional chromatographic system which utilized a mixed mode (C18 and anion exchange) column to trap the parent compound and glucuronide and a C18 column to separate the substrate and product. The IMER system was used for the online glucuronidation of 4-methylumbelliferone (4Me7OHC) and acetaminophen (APAP). The Michaelis-Menten kinetic parameters (Km and Vmax) associated with the formation of 4Me7OHC and APAP glucuronides demonstrated that the immobilization had not significantly affected the enzymatic activity of the UDPGT relative to the non-immobilized enzyme. The IMER retained enzymatic activity for more than 6 weeks. The results of this study demonstrate an easy and convenient way to identify compounds which may be glucuronidated and to synthesize and characterize the resulting products. PMID:16023900

Kim, Hee Seung; Wainer, Irving W

2005-09-01

163

Androgen glucuronides analysis by liquid chromatography tandem-mass spectrometry: could it raise new perspectives in the diagnostic field of hormone-dependent malignancies?  

PubMed

Breast and prostate constitute organs of intense steroidogenic activity. Clinical and epidemiologic data provide strong evidence on the influence of androgens and estrogens on the risk of typical hormone-dependent malignancies, like breast and prostate cancer. Recent studies have focused on the role of androgen metabolites in regulating androgen concentrations in hormone-sensitive tissues. Steroid glucuronidation has been suggested to have a prominent role in controlling the levels and the biological activity of unconjugated androgens. It is well-established that serum levels of androgen glucuronides reflect androgen metabolism in androgen-sensitive tissues. Quantitative analysis of androgen metabolites in blood specimens is the only minimally invasive approach permitting an accurate estimate of the total pool of androgens. During the past years, androgen glucuronides analysis most often involved radioimmunoassays (RIA) or direct immunoassays, both methods bearing serious limitations. However, recent impressive technical advances in mass spectrometry, and particularly in high performance liquid chromatography coupled with mass spectrometry (LC-MS/MS), have overcome these drawbacks enabling the simultaneous, quantitative analysis of multiple steroids even at low concentrations. Blood androgen profiling by LC-MS/MS, a robust and reliable technique of high selectivity, sensitivity, specificity, precision and accuracy emerges as a promising new approach in the study of human pathology. The present review offers a contemporary insight in androgen glucuronides profiling through the application of LC-MS/MS, highlighting new perspectives in the study of steroids and their implication in hormone-dependent malignancies. PMID:24140653

Kalogera, Eleni; Pistos, Constantinos; Provatopoulou, Xeni; Athanaselis, Sotirios; Spiliopoulou, Chara; Gounaris, Antonia

2013-12-01

164

Enantioselective Reformatsky reaction of ethyl iododifluoroacetate with ketones.  

PubMed

Two approaches have been developed for the enantioselective Reformatsky reaction of ethyl iododifluoroacetate with ketones to form a quaternary carbon centre using (1R,2S)-1-phenyl-2-(1-pyrrolidinyl)-1-propanol as the chiral ligand. Good yields and high enantioselectivities (80-91% ee) were achieved with a range of alkyl aryl ketones in a convenient one-pot protocol using ethyl iododifluoroacetate and diethylzinc to form the difluorinated Reformatsky reagent homogeneously. In the traditional two-step Reformatsky reaction using the preformed Reformatsky reagent generated from ethyl iododifluoroacetate and zinc dust, good yields and good enantioselectivities (75-84% ee) were also obtained. PMID:22421710

Fornalczyk, Michal; Singh, Kuldip; Stuart, Alison M

2012-04-28

165

Non-steroidal anti-inflammatory drugs do not influence the urinary testosterone/epitestosterone glucuronide ratio.  

PubMed

The UDP Glucuronosyl Transferase (UGT) enzymes are important in the pharmacokinetics, and conjugation, of a variety of drugs including non-steroidal anti-inflammatory drugs (NSAIDs) as well as anabolic androgenic steroids (AAS). Testosterone glucuronidation capacity is strongly associated with a deletion polymorphism in the UGT2B17 gene. As the use of high doses of NSAIDs has been observed in athletes there is a risk for a drug-drug interaction that may influence the doping tests for AAS. In vitro studies show inhibitory potential on UGT2B7, 2B15, and 2B17 enzymes by NSAIDs. The aim of this study was to investigate if concomitant use of NSAIDs and a single dose of testosterone enanthate would affect the excretion rate of testosterone and epitestosterone glucuronide (TG and EG) as well as the T/E ratio, thereby affecting the outcome of the testosterone doping test. The study was designed as an open, randomized, cross-over study with subjects being their own control. The 23 male healthy volunteers, with either two, one or no allele (ins/ins, ins/del, or del/del) of the UGT2B17 gene, received the maximum recommended dose of NSAID (Ibuprofen or Diclofenac) for 6?days. On day three, 500?mg of testosterone enanthate was administered. Spot urine samples were collected for 17?days. After a wash-out period of 4?months the volunteers received 500?mg testosterone enanthate only, with subsequent spot urine collection for 14?days. The glucuronides of testosterone and epitestosterone were quantified. NSAIDs did not affect the excretion of TG or EG before the administration of testosterone. The concomitant use of NSAIDs and testosterone slightly increased the TG excretion while the EG excretion was less suppressed compared to testosterone use only. The effects of the NSAIDs on the TG and EG excretion did not differ between the UGT2B17 genotype groups. In conclusion, the outcome of testosterone doping tests does not seem to be affected by the use of NSAIDs. PMID:23720652

Lundmark, Jonas; Gårevik, Nina; Thörngren, John-Olof; Garle, Mats; Ekström, Lena; Rane, Anders; Schulze, Jenny J

2013-01-01

166

Non-Steroidal Anti-Inflammatory Drugs Do Not Influence the Urinary Testosterone/Epitestosterone Glucuronide Ratio  

PubMed Central

The UDP Glucuronosyl Transferase (UGT) enzymes are important in the pharmacokinetics, and conjugation, of a variety of drugs including non-steroidal anti-inflammatory drugs (NSAIDs) as well as anabolic androgenic steroids (AAS). Testosterone glucuronidation capacity is strongly associated with a deletion polymorphism in the UGT2B17 gene. As the use of high doses of NSAIDs has been observed in athletes there is a risk for a drug–drug interaction that may influence the doping tests for AAS. In vitro studies show inhibitory potential on UGT2B7, 2B15, and 2B17 enzymes by NSAIDs. The aim of this study was to investigate if concomitant use of NSAIDs and a single dose of testosterone enanthate would affect the excretion rate of testosterone and epitestosterone glucuronide (TG and EG) as well as the T/E ratio, thereby affecting the outcome of the testosterone doping test. The study was designed as an open, randomized, cross-over study with subjects being their own control. The 23 male healthy volunteers, with either two, one or no allele (ins/ins, ins/del, or del/del) of the UGT2B17 gene, received the maximum recommended dose of NSAID (Ibuprofen or Diclofenac) for 6?days. On day three, 500?mg of testosterone enanthate was administered. Spot urine samples were collected for 17?days. After a wash-out period of 4?months the volunteers received 500?mg testosterone enanthate only, with subsequent spot urine collection for 14?days. The glucuronides of testosterone and epitestosterone were quantified. NSAIDs did not affect the excretion of TG or EG before the administration of testosterone. The concomitant use of NSAIDs and testosterone slightly increased the TG excretion while the EG excretion was less suppressed compared to testosterone use only. The effects of the NSAIDs on the TG and EG excretion did not differ between the UGT2B17 genotype groups. In conclusion, the outcome of testosterone doping tests does not seem to be affected by the use of NSAIDs. PMID:23720652

Lundmark, Jonas; Garevik, Nina; Thorngren, John-Olof; Garle, Mats; Ekstrom, Lena; Rane, Anders; Schulze, Jenny J.

2013-01-01

167

Nicotine N-glucuronidation relative to N-oxidation and C-oxidation and UGT2B10 genotype in five ethnic/racial groups.  

PubMed

Nicotine metabolism influences smoking behavior and differences in metabolism probably contribute to ethnic variability in lung cancer risk. We report here on the proportion of nicotine metabolism by cytochrome P450 2A6-catalyzed C-oxidation, UDP-glucuronosyl transferase 2B10 (UGT2B10)-catalyzed N-glucuronidation and flavin monooxygenase 3-catalyzed N-oxidation in five ethnic/racial groups and the role of UGT2B10 genotype on the metabolic patterns observed. Nicotine and its metabolites were quantified in urine from African American (AA, n = 364), Native Hawaiian (NH, n = 311), White (n = 437), Latino (LA, n = 453) and Japanese American (JA, n = 674) smokers. Total nicotine equivalents, the sum of nicotine and six metabolites, and nicotine metabolism phenotypes were calculated. The relationship of UGT2B10 genotype to nicotine metabolic pathways was determined for each group; geometric means were computed and adjusted for age, sex, creatinine, and body mass index. Nicotine metabolism patterns were unique across the groups, C-oxidation was lowest in JA and NH (P < 0.0001), and N-glucuronidation lowest in AA (P < 0.0001). There was no difference in C-oxidation among Whites and AA and LA. Nicotine and cotinine glucuronide ratios were 2- and 3-fold lower in AA compared with Whites. Two UGT variants, a missense mutation (Asp67Tyr, rs61750900) and a splice variant (rs116294140) accounted for 33% of the variation in glucuronidation. In AA, the splice variant accounted for the majority of the reduced nicotine glucuronidation. UGT2B10 variant allele carriers had increased levels of C-oxidation (P = 0.0099). Our data indicate that the relative importance of nicotine metabolic pathways varies by ethnicity, and all pathways should be considered when characterizing the role of nicotine metabolism on smoking behavior and cancer risk. PMID:25233931

Murphy, Sharon E; Park, Sung-Shim L; Thompson, Elizabeth F; Wilkens, Lynne R; Patel, Yesha; Stram, Daniel O; Le Marchand, Loic

2014-11-01

168

Health and environmental effects profile for ethyl acetate  

SciTech Connect

The Health and Environmental Effects Profile for ethyl acetate was prepared to support listings of hazardous constituents of a wide range of waste streams under Section 3001 of the Resource Conservation and Recovery Act (RCRA) and to provide health-related limits for emergency actions under Section 101 of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). Both published literature and information obtained from Agency program office files were evaluated as they pertained to potential human-health, aquatic-life and environmental effects of hazardous-waste constituents. Ethyl acetate has been determined to be a systemic toxicant. The daily exposure to the human population (including sensitive subgroups) that is likely to be without appreciable risk of deleterious effect during a lifetime, for ethyl acetate is 0.9 mg/kg/day for oral exposure. The Reportable Quantity (RQ) value for ethyl acetate is 1000.

Not Available

1986-12-01

169

Health and environmental effects profile for ethyl acrylate  

SciTech Connect

The Health and Environmental Effects Profile for ethyl acrylate was prepared to support listings of hazardous constituents of a wide range of waste streams under Section 3001 of the Resource Conservation and Recovery Act (RCRA) and to provide health-related limits for emergency actions under Section 101 of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). Both published literature and information obtained from Agency program office files were evaluated as they pertained to potential human-health, aquatic-life and environmental effects of hazardous-waste constituents. Ethyl acrylate has been evaluated as a carcinogen. The human carcinogen potency factor (q1*) for ethyl acrylate is .048/mg/kg/day for oral exposure. The Reportable Quantity (RQ) value for ethyl acrylate is 1000.

Not Available

1987-05-01

170

Ethyl Carbamate in Foods and Beverages – A Review  

Microsoft Academic Search

\\u000a Foods and beverages contain many toxic chemicals that raise health concerns. Ethyl carbamate (EC) or urethane is the ethyl\\u000a ester of carbamic acid. It occurs at low levels, from ng\\/L to mg\\/L, in many fermented foods and beverages. EC is genotoxic\\u000a and carcinogenic for a number of species such as mice, rats, hamsters and monkeys. It has been classified as

J. V. Weber; V. I. Sharypov

171

Effects of Ethyl Alcohol on Canine Jejunal Circular Smooth Muscle  

Microsoft Academic Search

Ethyl alcohol has many symptomatic effects onthe gastrointestinal tract. Our aim was to determine theeffects of ethyl alcohol on circular smooth musclecontractility of the canine small bowel. Mechanical and intracellular electrical recordings weremade in vitro from the circular muscle of full-thicknessstrips of muscularis externa from canine jejunum. Ethylalcohol (20-120 mM) dose-dependently decreased spontaneous contractile amplitude,hyperpolarized the resting membrane potential, anddecreased

Gang Lu; Michael G. Sarr; Joseph H. Szurszewski

1997-01-01

172

Sonochemical enantioselective hydrogenation of ethyl pyruvate over platinum catalysts  

Microsoft Academic Search

Chiral sonochemical hydrogenation of an aliphatic ?-ketoester, ethyl pyruvate to ethyl lactate was carried out over various platinum catalysts in different solvents under atmospheric hydrogen pressure. The reaction rates and the enantiomeric excesses were determined over Pt\\/C, Pt\\/SiO2 and Pt\\/K-10 catalysts both under conventional and sonochemical conditions. The effect of ultrasounds on the catalytic activity and enantioselectivity was tested applying

Béla Török; Károly Felföldi; Gerda Szakonyi; Mihály Bartók

1997-01-01

173

The Impact of Glucuronidation on the Bioactivation and DNA Adduction of the Cooked-Food Carcinogen 2-Amino-1-methyl-6-phenylimidazo[4,5-b] pyridine in vivo  

SciTech Connect

UDP-glucuronosyltransferases (UGTs) catalyze the glucuronidation of many different chemicals. Glucuronidation is especially important for detoxifying reactive intermediates from metabolic reactions, which otherwise can be biotransformed into highly reactive cytotoxic or carcinogenic species. Detoxification of certain food-borne carcinogenic heterocyclic amines (HAs) is highly dependent on UGT1A-mediated glucuronidation. 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), the most mass abundant carcinogenic HA found in well-done cooked meat, is extensively glucuronidated by UGT1A proteins. In humans, CYP1A2 catalyzed N-hydroxylation and subsequent UGT1A-mediated glucuronidation is a dominant pathway in the metabolism of PhIP. Therefore, changes in glucuronidation rates could significantly alter PhIP metabolism. To determine the importance of UGT1A-mediated glucuronidation in the biotransformation of PhIP, UGT1A proficient Wistar and UGT1A deficient Gunn rats were exposed to a single 100 {micro}g/kg oral dose of [{sup 14}C]-PhIP. Urine was collected over 24 h and the PhIP urinary metabolite profiles were compared between the two strains. After the 24 h exposure, livers and colon were removed and analyzed for DNA adduct formation by accelerator mass spectrometry. Wistar rats produced several PhIP and N-hydroxy-PhIP glucuronides that accounted for {approx}25% of the total amount of recovered urinary metabolites. In the Gunn rats, PhIP and N-hydroxy-PhIP glucuronides were reduced by 68-92%, compared to the Wistar rats, and comprised only 4% of the total amount of recovered urinary metabolites. PhIP-DNA adduct analysis from the Gunn rats revealed a correlation between reduced PhIP and N-hydroxy-PhIP glucuronide levels in the urine and increased hepatic DNA adducts, compared to the Wistar rats. These results indicate that UGT1A-mediated glucuronidation of PhIP and N-hydroxy-PhIP is an important pathway for PhIP detoxification. Failure to form glucuronide conjugates results in increases in PhIP bioactivation and DNA adduct formation, which can potentially lead to increases in tumor formation. Therefore, diminished UGT1A activity could pose a significant risk for the development of certain cancers from exposure to PhIP.

Malfatti, M A; Ubick, E A; Felton, J S

2005-03-31

174

Limitations of hepatocytes and liver homogenates in modelling in vivo formation of acyl glucuronide-derived drug-protein adducts.  

PubMed

The covalent binding of drugs or their metabolites to proteins is of increasing interest in the investigation of the toxicity of these compounds. Recent attention on biological consequences of protein adduct formation with carboxylate drugs, derived via their reactive acyl glucuronide metabolites, has focussed on liver tissue. Although the intact animal represents undisturbed hepatic physiology, other hepatic models can offer advantages, e.g., multiple experiments from a single liver. In this study we set out to compare the patterns of covalent binding of zomepirac (ZP) to proteins in the livers of intact rats, isolated rat hepatocytes (in culture or suspension), and in rat liver homogenates. Rats were dosed i.v. with 25 mg ZP/kg, and their livers were removed 3 h later. Isolated hepatocytes or liver homogenates were exposed to ZP at 100 microg/mL for 3 h at 37 degrees C. Liver homogenates were exposed to ZP and also zomepirac acyl glucuronide (ZAG) at 100 microg ZP equivalents/mL for 3 h at 37 degrees C. Covalent binding of ZP species was examined by SDS-PAGE and Western blotting with a polyclonal ZP antiserum. In livers from dosed animals, the strongest staining appeared at about 110120, 140, and 200 kDa. Few similarities existed with the results from isolated hepatocytes and, not surprisingly, liver homogenates. Only the 200-kDa band was common to all treatments. Many proteins seemed to be modified, at least to some extent. The differences in major bands are most likely caused by the loss of liver and hepatocyte architecture. The variability across different model systems in respect to covalent binding to hepatic proteins emphasizes the need for care in interpretation of results. PMID:10507755

Bailey, M J; Dickinson, R G

1999-02-01

175

Is urine an alternative to cosmetically treated hair for the detection of drugs and alcohol?  

PubMed

This study attempts to assess the utility of the urine matrix as an alternative to cosmetically treated hair for the detection of drugs and alcohol for driving licence re-granting in 1026 cosmetically treated hair samples and 33 262 urine routine samples. No significant difference was observed between the percentage positive samples in cosmetically treated hair to those in urine at both the 95% and 99% significance level for amphetamines, cocaine, opiates, benzodiazepines, and methadone. Significant difference was found between the positivity rates of cannabinoids in cosmetically treated hair and that in urine indicating urine to be a better alternative to the use of the hair matrix even when cosmetically treated. The opposite was observed for the alcohol consumption marker ethyl glucuronide (EtG) for which the positivity rate in cosmetically treated hair was twice that in urine samples. Particularly for alcohol abstinence monitoring, as for the rehabilitative driving licence re-granting medical and psychological assessment (MPA) programme in Germany, it seems that ethyl glucuronide (EtG) in hair presents a much better alternative than urine testing, even when cosmetically treated hair is analyzed. Moreover, segmentation is an additional advantage of hair testing which can provide additional useful information. PMID:24817057

Agius, Ronald; Dufaux, Bertin; Kahl, Hans-Gerhard; Nadulski, Thomas

2014-06-01

176

Meconium Indicators of Maternal Alcohol Abuse during Pregnancy and Association with Patient Characteristics  

PubMed Central

Aim. Identification of women with moderate alcohol abuse during pregnancy is difficult. We correlated self-reported alcohol consumption during pregnancy and patient characteristics with objective alcohol indicators measured in fetal meconium. Methods. A total of 557 women singleton births and available psychological tests, obstetric data and meconium samples were included in statistical analysis. Alcohol metabolites (fatty acid ethyl esters (FAEEs) and ethyl glucuronide (EtG)), were determined from meconium and correlated with patient characteristics. Results. We found that 21.2% of the 557 participants admitted low-to-moderate alcohol consumption during pregnancy. Of the parameters analyzed from meconium, only EtG showed an association with alcohol history (P < 0.01). This association was inverse in cases with EtG value above 120?ng/g. These values indicate women with most severe alcohol consumption, who obviously denied having consumed alcohol during pregnancy. No other associations between socioeconomic or psychological characteristics and the drinking status (via meconium alcohol metabolites) could be found. Conclusion. Women who drink higher doses of ethanol during pregnancy, according to metabolite measures in meconium, might be less likely to admit alcohol consumption. No profile of socioeconomic or psychological characteristics of those women positively tested via meconium could be established. PMID:24800249

Goecke, Tamme W.; Burger, Pascal; Fasching, Peter A.; Bakdash, Abdulsallam; Engel, Anne; Haberle, Lothar; Voigt, Franziska; Faschingbauer, Florian; Raabe, Eva; Maass, Nicolai; Rothe, Michael; Beckmann, Matthias W.; Pragst, Fritz

2014-01-01

177

40 CFR 721.3152 - Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...  

Code of Federal Regulations, 2010 CFR

...fatty acids, ethyl sulfates (salts). 721.3152 Section 721...fatty acids, ethyl sulfates (salts). (a) Chemical substance...fatty acids, ethyl sulfates (salts) (P-94-24) is subject...present a risk of injury to human health or the environment...

2010-07-01

178

40 CFR 721.3152 - Ethanaminium, N-ethyl-2-hydroxy-N,N-bis(2-hydroxyethyl)-, diester with C12-18 fatty acids, ethyl...  

Code of Federal Regulations, 2011 CFR

...fatty acids, ethyl sulfates (salts). 721.3152 Section 721...fatty acids, ethyl sulfates (salts). (a) Chemical substance...fatty acids, ethyl sulfates (salts) (P-94-24) is subject...present a risk of injury to human health or the environment...

2011-07-01

179

Defective induction of phenol glucuronidation by 3-methylcholanthrene in Gunn rats is due to the absence of a specific UDP-glucuronosyltransferase isoenzyme.  

PubMed

Antiserum directed against purified rat kidney UDP-glucuronosyltransferase (UDPGT) was raised in goats. IgG prepared from this antiserum exhibited specificity for only two UDPGT isoenzymes (bilirubin and phenol) on immunoblot analysis of Wistar rat liver microsomes. Use of this antibody preparation to probe Western blots of liver microsomes prepared from Gunn rats confirmed that the defective phenol glucuronidation was due to the absence of a 53-kDa, 3-methylcholanthrene-inducible UDPGT isoenzyme. Results obtained from enzyme activity measurements and immunoblot analysis of microsomes isolated from xenobiotic-treated Wistar and Gunn rat liver are consistent with the 3-methylcholanthrene/UDPGT induction deficiency in the Gunn rat being due to the absence of this phenol UDPGT isoenzyme. The contribution of other UDPGT isoenzymes to the greatly reduced glucuronidation of planar phenols observed in the Gunn rat is discussed. PMID:3110589

Coughtrie, M W; Burchell, B; Shepherd, I M; Bend, J R

1987-06-01

180

Design of experiments, a powerful tool for method development in forensic toxicology: application to the optimization of urinary morphine 3-glucuronide acid hydrolysis  

Microsoft Academic Search

The application of the design of experiments to optimize method development in the field of forensic toxicology using the\\u000a urinary morphine 3-glucuronide acid hydrolysis as an example is described. Morphine and its trideuterated analogue (used as\\u000a an internal standard) were extracted from urine samples by liquid–liquid extraction (ToxiTubes® A) and derivatized by silylation.\\u000a Chromatographic analysis was done by gas chromatography–mass

S. Costa; M. Barroso; A. Castañera; M. Dias

2010-01-01

181

Familial resemblance for free androgens and androgen glucuronides in sedentary black and white individuals: the HERITAGE Family Study. Health, Risk Factors, Exercise Training and Genetics.  

PubMed

Familial correlation analyses were used to evaluate the familial aggregation of plasma androgens and androgen glucuronides (testosterone (TESTO), dihydrotestosterone (DHT), androstane-3 alpha,17 beta-diol glucuronide (3 alpha-DIOL-G), and androsterone glucuronide (ADT-G)) in 505 members of 99 white families and 296 members of 111 black families participating in the Health, Risk Factors, Exercise Training and Genetics (HERITAGE) Family Study. Each of these four measures was determined by RIA after separation of conjugated and unconjugated steroid using C18 column chromatography. All participants were sedentary prior to being including in this study. Significant spouse correlations, as well as parent-offspring and sibling correlations, were found for TESTO, DHT, 3 alpha-DIOL-G, and ADT-G in the white sample, suggesting that common familial environments and genes contribute to the familial resemblance. In the black sample, significant sibling and parent-offspring correlations were found for all four phenotypes, while the spouse correlation was marginally significant for 3 alpha-DIOL-G and not significant for TESTO, DHT, and ADT-G. The non-significance of spouse correlations in the black individuals may be due to the small number of spouse pairs. The maximal heritability estimates of TESTO, DHT, 3 alpha-DIOL-G, and ADT-G were 69%, 87%, 74%, and 56% for white individuals and 70%, 73%, 62%, and 48% for black individuals respectively. Sex differences in heritability estimates were found in the white individuals, but they were less dramatic in the black individuals. In conclusion, plasma levels of androgens and androgen glucuronides are highly heritable in both white individuals and black individuals. There are notable sex differences in the white individuals. PMID:11479145

Hong, Y; Gagnon, J; Rice, T; Pérusse, L; Leon, A S; Skinner, J S; Wilmore, J H; Bouchard, C; Rao, D C

2001-08-01

182

Evaluation of In Situ Generated Valproyl 1-O-?-Acyl Glucuronide in Valproic Acid Toxicity in Sandwich-Cultured Rat Hepatocytes.  

PubMed

Acyl glucuronides are reactive electrophilic metabolites implicated in the toxicity of carboxylic acid drugs. Valproyl 1-O-?-acyl glucuronide (VPA-G), which is a major metabolite of valproic acid (VPA), has been linked to the development of oxidative stress in VPA-treated rats. However, relatively little is known about the toxicity of in situ generated VPA-G and its contribution to VPA hepatotoxicity. Therefore, we investigated the effects of modulating the in situ formation of VPA-G on lactate dehydrogenase (LDH) release (a marker of necrosis), BODIPY 558/568 C12 accumulation (a marker of steatosis), and cellular glutathione (GSH) content in VPA-treated sandwich-cultured rat hepatocytes. VPA increased LDH release and BODIPY 558/568 C12 accumulation, whereas it had little or no effect on total GSH content. Among the various uridine 5'-diphospho-glucuronosyltransferase inducers evaluated, ?-naphthoflavone produced the greatest increase in VPA-G formation. This was accompanied by an attenuation of the increase in BODIPY 558/568 C12 accumulation, but did not affect the change in LDH release or total GSH content in VPA-treated hepatocytes. Inhibition of in situ formation of VPA-G by borneol was not accompanied by substantive changes in the effects of VPA on any of the toxicity markers. In a comparative study, in situ generated diclofenac glucuronide was not toxic to rat hepatocytes, as assessed using the same chemical modulators, thereby demonstrating the utility of the sandwich-cultured rat hepatocyte model. Overall, in situ generated VPA-G was not toxic to sandwich-cultured rat hepatocytes, suggesting that VPA glucuronidation per se is not expected to be a contributing mechanism for VPA hepatotoxicity. PMID:25147275

Surendradoss, Jayakumar; Chang, Thomas K H; Abbott, Frank S

2014-11-01

183

NEW GROUND-STATE MEASUREMENTS OF ETHYL CYANIDE  

SciTech Connect

The spectrum of ethyl cyanide, or propionitrile (CH{sub 3}CH{sub 2}CN), has been repeatedly observed in the interstellar medium with large column densities and surprisingly high temperatures in hot core sources. The construction of new, more sensitive, observatories accessing higher frequencies such as Herschel, ALMA, and SOFIA have made it important to extend the laboratory data for ethyl cyanide to coincide with the capabilities of the new instruments. We report extensions of the laboratory measurements of the rotational spectrum of ethyl cyanide in its ground vibrational state to 1.6 THz. A global analysis of the ground state, which includes all of the previous data and 3356 newly assigned transitions, has been fitted to within experimental error to J = 132, K = 36, using both Watson A-reduced and Watson S-reduced Hamiltonians.

Brauer, Carolyn S.; Pearson, John C.; Drouin, Brian J.; Yu, Shanshan [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)], E-mail: Carolyn.S.Brauer@jpl.nasa.gov

2009-09-01

184

Selective determination of ethyl acetate, acetone, ethanol, and methyl ethyl ketone using quartz crystal nanobalance combined with principle component analysis.  

PubMed

Quartz crystal nanobalance (QCN) sensors are considered as powerful mass sensitive sensors to determine materials in the subnanogram level. In the current study a method based on QCN modified with polyethylene glycol (PEG) has been developed to determine organic vapors (ethyl acetate, acetone, ethanol and methyl ethyl ketone). The frequency shift of QCN was found to be linear against analytes concentrations in the range between 4 to 35 mg/L for acetone vapor and 4-70 mg/L for 3 other vapors. The correlation coefficients for ethyl acetate, acetone, ethanol, and methyl ethyl ketone were 0.9971, 0.9976, 0.9984 and 0.9927, respectively. The principal component analysis was also utilized to process the frequency response data of the organic vapors. Using principal component analysis, it was found that over 95% of the data variance could still be explained by use of two principal components (PC1 and PC2). Subsequently, the successful discrimination of ethyl acetate and other compounds was possible through the principal component analysis of the transient responses of the PEG-modified QCN sensor. PMID:19799053

Mirmohseni, A; Razzaghi, M A; Pourata, R; Rastgouye-Hojagan, M; Zavareh, S

2009-07-15

185

Pregnane x Receptor (PXR) expression in colorectal cancer cells restricts irinotecan chemosensitivity through enhanced SN-38 glucuronidation  

PubMed Central

Background Clinical efficacy of chemotherapy in colorectal cancer is subjected to broad inter-individual variations leading to the inability to predict outcome and toxicity. The topoisomerase I inhibitor irinotecan (CPT-11) is worldwide approved for the treatment of metastatic colorectal cancer and undergoes extensive peripheral and tumoral metabolism. PXR is a xenoreceptor activated by many drugs and environmental compounds regulating the expression of drug metabolism and transport genes in detoxification organs such as liver and gastrointestinal tract. Considering the metabolic pathway of irinotecan and the tissue distribution of Pregnane × Receptor (PXR), we hypothesized that PXR could play a key role in colon cancer cell response to irinotecan. Results PXR mRNA expression was quantified by RT-quantitative PCR in a panel of 14 colon tumor samples and their matched normal tissues. PXR expression was modulated in human colorectal cancer cells LS174T, SW480 and SW620 by transfection and siRNA strategies. Cellular response to irinotecan and its active metabolic SN38 was assessed by cell viability assays, HPLC metabolic profiles and mRNA quantification of PXR target genes. We showed that PXR was strongly expressed in colon tumor samples and displayed a great variability of expression. Expression of hPXR in human colorectal cancer cells led to a marked chemoresistance to the active metabolite SN38 correlated with PXR expression level. Metabolic profiles of SN38 showed a strong enhancement of SN38 glucuronidation to the inactive SN38G metabolite in PXR-expressing cells, correlated with an increase of UDPglucuronosyl transferases UGT1A1, UGT1A9 and UGT1A10 mRNAs. Inhibition of PXR expression by lentivirus-mediated shRNA, led to SN38 chemoresistance reversion concomitantly to a decrease of UGT1A1 expression and SN38 glucuronidation. Similarly, PXR mRNA expression levels correlated to UGT1A subfamily expression in human colon tumor biopsies. Conclusion Our results demonstrate that tumoral metabolism of SN38 is affected by PXR and point to potential therapeutic significance of PXR quantification in the prediction of irinotecan response. Furthermore, our observations are pharmacologically relevant since many patients suffering from cancer diseases are often exposed to co-medications, food additives or herbal supplements able to activate PXR. A substantial part of the variability observed among patients might be caused by such interactions PMID:20196838

2010-01-01

186

Simultaneous determination of three glucuronide conjugates of scutellarein in rat plasma by LC-MS/MS for pharmacokinetic study of breviscapine.  

PubMed

A selective and sensitive LC-MS/MS method was developed and validated for simultaneous determination of three glucuronide conjugates of scutellarein in rat plasma. Plasma samples were pretreated by protein precipitation with acetonitrile. The analytes (scutellarin, scutellarein-6,7-di-O-?-d-glucuronide and scutellarein-6-O-?-d-glucuronide), together with internal standard (IS, baicalin) were separated on a Diamonsil C18 column (150 mm × 4.6 mm, 5 ?m) with an isocratic mobile phase consisting of methanol-water-formic acid (55:45:0.2, v/v/v). Mass spectrometric detection was performed by selected reaction monitoring (SRM) mode via electrospray ionization source operating in negative ionization mode. The method was linear for all the analytes over the investigated concentration ranges with correlation coefficients greater than 0.9954. The intra- and inter-day precisions were less than 9.1% and the relative error was between -1.7% and 4.2%. The extraction recoveries of the analytes and IS from rat plasma were over 63%. The validated method has been successfully applied to a pharmacokinetic study of breviscapine in rats after intragastric administration at a dose of 20mg/kg. The pharmacokinetic results would be helpful to better understand the pharmacological actions of breviscapine. PMID:24999248

Wang, Xin; Xia, Hongjun; Liu, Youping; Qiu, Feng; Di, Xin

2014-08-15

187

Identification of ractopamine glucuronides and determination of bioactive ractopamine residues and its metabolites in food animal urine by ELISA, LC-MS/MS and GC-MS.  

PubMed

Ractopamine glucuronides have been identified in cattle urine sampled by LC-MS/MS. An ELISA method, which was capable of specifically determining (1R, 3R)-ractopamine stereoisomer and its glucuronide metabolites, had more than 100% recovery with an acceptable coefficient of variation in the inter- and intra-assay variation tests for RR-ractopamine. The concentration levels of parent ractopamine and ractopamine glucuronide metabolites as the main components of total ractopamine in cattle and sheep urine showed similar depletion trends, in which the concentration curves increased and reached a climax during the feeding period, and then dropped quickly when entering the withdrawal period. Data from the three methods had very good pair-wise correlations. In the cattle urine samples, the correlation coefficient (R(2)) for parent ractopamine between the ELISA and the LC-MS/MS or GC-MS results were 0.93 or 0.92; R(2) values for parent ractopamine and total ractopamine data measured by LC-MS/MS and GC-MS were 0.9651 and 0.9677, respectively. All R(2) values for data gained from sheep urine samples were >0.95. The study indicated that the close levels of RR-ractopamine stereoisomer in cattle and sheep urine samples may imply the presence of a similar depletion pattern in other livestock, and thus would facilitate an accurate detection and management of ractopamine usage in food safety. PMID:24444392

Jiang, Xiao-Fei; Zhu, Yue-Hui; Liu, Xiao-Yun

2014-01-01

188

Accurate Prediction of Glucuronidation of Structurally Diverse Phenolics by Human UGT1A9 Using Combined Experimental and In Silico Approaches  

PubMed Central

Purpose The catalytic selectivity of human UGT1A9, an important membrane-bound enzyme catalyzing glucuronidation of xenobiotics were determined experimentally using 145 phenolics, and analyzed by 3D-QSAR methods. Methods The catalytic efficiency of UGT1A9 was determined by kinetic profiling. Quantitative structure activity relationships were analyzed using the CoMFA and CoMSIA techniques. Molecular alignment of the substrate structures was made by superimposing the glucuronidation site and its adjacent aromatic ring to achieve maximal steric overlap. For a substrate with multiple active glucuronidation sites, each site was considered as a separate substrate. Results The 3D-QSAR analyses produced statistically reliable models with good predictive power (CoMFA: q2 = 0.548, r2= 0.949, r2pred = 0.775; CoMSIA: q2 = 0.579, r2= 0.876, r2pred = 0.700). The contour coefficient maps were applied to elucidate structural features among substrates that are responsible for the selectivity differences. Furthermore, the contour coefficient maps were overlaid in the catalytic pocket of a homology model of UGT1A9; this enabled us to identify the UGT1A9 catalytic pocket with a high degree of confidence. Conclusion The CoMFA/CoMSIA models can predict the substrate selectivity and in vitro clearance of UGT1A9. Our findings also provide a possible molecular basis for understanding UGT1A9 functions and its substrate selectivity. PMID:22302521

Wu, Baojian; Wang, Xiaoqiang; Zhang, Shuxing; Hu, Ming

2012-01-01

189

Spectroscopic characterization and detection of Ethyl Mercaptan in Orion  

E-print Network

New laboratory data of ethyl mercaptan, CH$_{3}$CH$_{2}$SH, in the millimeter and submillimeter-wave domains (up to 880 GHz) provided very precise values of the spectroscopic constants that allowed the detection of $gauche$-CH$_3$CH$_2$SH towards Orion KL. 77 unblended or slightly blended lines plus no missing transitions in the range 80-280 GHz support this identification. A detection of methyl mercaptan, CH$_{3}$SH, in the spectral survey of Orion KL is reported as well. Our column density results indicate that methyl mercaptan is $\\simeq$ 5 times more abundant than ethyl mercaptan in the hot core of Orion KL.

Kolesniková, L; Cernicharo, J; Alonso, J L; Daly, A M; Gordon, B P; Shipman, S T

2014-01-01

190

Molecular interactions in alcohol-ethyl methacrylate mixtures  

NASA Astrophysics Data System (ADS)

Molecular interaction between alcohols (1-propanol, 1-butanol, s-butanol, t-butanol, 1-pentanol, 1-heptanol, 1-octanol and 1-decanol) with ethyl methacrylate has been studied in n-heptane, CCl 4 and benzene at 298 K using FTIR spectroscopic and dielectric methods. The result obtained from both the methods indicates only the existence of most likely 1:1 complex formation between the alcohol and ethyl methacrylate in these systems. The alkyl chain length of alcohol and the solvent used play a significant role in the strength of hydrogen bond (O sbnd H:O dbnd C) determined on the basis of spectral and dielectric parameters.

Dharmalingam, K.; Ramachandran, K.; Sivagurunathan, P.; Kalamse, G. M.

2008-02-01

191

Ethyl sulphate, a chemically reactive human metabolite of ethanol?  

PubMed

Abstract 1.?Ethanol consumption is known to be linked in varying degrees to numerous ailments including damage to the nervous, endocrine and musculoskeletal systems and the gastrointestinal tract as well as extensive liver injury and several cancerous events. 2.?Although acetaldehyde is the presently favoured candidate, both directly and indirectly, for such deleterious outcomes, over the years many other mechanisms and suggestions have been advanced. 3.?The sparse literature concerning ethyl sulphate, a recently confirmed human metabolite of ethanol, has been examined, evaluated and interpreted to put forward the new proposition that ethyl sulphate itself may be able to alkylate various biological macromolecules thereby leading to toxicity. PMID:25034011

Mitchell, Stephen C; Waring, Rosemary H; Wilson, Ian D

2014-11-01

192

Ground-state stability and rotational activation parameters for individual rotamers of (R,S,S,R)-(N,N'-dimethyl-2,3-diaminobutane)PtG(2) complexes (G = 9-EtG, 3'-GMP, and 5'-GMP).  

PubMed

Rate constants for guanine rotation about the Pt-N7 bond in (R,S,S,R)-Me(2)DABPtG(2) complexes (Me(2)DAB = N,N'-dimethyl-2,3-diaminobutane; G = 9-EtG, 3'-GMP, and 5'-GMP) were evaluated from line-shape analysis of H8 resonances. Three diastereomers, two in head-to-tail (DeltaHT and LambdaHT) and one in head-to-head (HH) conformations, exist in equilibrium in solution. The two guanines are equivalent in DeltaHT and LambdaHT conformers and nonequivalent in the HH form; therefore, four rate constants (k(Delta)(HT), k(Lambda)(HT), k(HH)()s, and k(HH)()d; sub-subscripts s and d stand for H8-shielded and -deshielded guanine, respectively) were evaluated. Activation parameters (DeltaH and DeltaS) were evaluated from the rate constant dependence on temperature. High values of DeltaH (78-93 kJ mol(-)(1)) and DeltaS (51-71 J K(-)(1) mol(-)(1)) were found for G rotation in the preferred DeltaHT rotamer having the six-membered ring of each guanine more canted toward the cis-G and a favorable dipole-dipole internucleotide interaction. Lower values of DeltaH() (64-76 kJ mol(-)(1)) and very small values of DeltaS() (-7-11 J K(-)(1) mol(-)(1)) were found for G rotation in the less favorable LambdaHT rotamer, indicating that the ground-state entropy of this rotamer is close to that of the activated complex and the ground-state enthalpy closer to that of the activated complex than for the DeltaHT rotamer. For the two guanines in the HH rotamer there is no large difference in activation parameters. In general DeltaH falls in the range 66-84 kJ mol(-)(1) (rather close to the values for the LambdaHT rotamer) and DeltaS in the range 14-41 J K(-)(1) mol(-)(1). The equilibrium constant between HT and HH rotamers was also evaluated together with the corresponding thermodynamic parameters (DeltaH and DeltaS). It is found that the low enthalpy is the major stabilizing factor for DeltaHT as compared to HH, while the entropy factor would favor the latter rotamer. In contrast the greater entropy is the stabilizing factor for the LambdaHT rotamer (the second most abundant conformer for 9-EtG and 3'-GMP) over the HH rotamer. In the latter case the enthalpy would favor the HH rotamer. In the case of the 5'-GMP derivative the greater entropy of the LambdaHT rotamer is not such to compensate for the lower enthalpy of the HH rotamer, and the latter remains the second most abundant rotamer. This investigation has allowed for the first time the enthalpic and entropic contributions favoring different rotamers to be distinguished. PMID:12588131

Colonna, Gianpiero; Di Masi, Nicola G; Marzilli, Luigi G; Natile, Giovanni

2003-02-24

193

Synthesis and Characterization of New Optically Active Poly (ethyl L-lysinamide)s and Poly (ethyl L-lysinimide)s  

PubMed Central

Ethyl L-lysine dihydrochloride was reacted with three different dianhydrides to yield the poly (ethyl L-lysinimide)s (PI1?3); it was also reacted with two different diacyl chlorides to yield the poly (ethyl L-lysinamide)s (PA4-5). The resulting polymers have inherent viscosities in the range of 0.15 to 0.42?dL?g?1. These polymers are prepared from an inexpensive starting material and are optically active, potentially ion exchangeable, semicrystalline, thermally stable, and soluble in polar aprotic solvents such as DMF, DMSO, NMP, DMAc, and sulfuric acid. All of the above polymers were fully characterized by FT-IR and 1H NMR spectroscopy, elemental analysis, WAX diffraction, TGA, inherent viscosity measurement, and specific rotation. PMID:22331998

Zahmatkesh, Saeed; Vakili, Mohammad Reza

2010-01-01

194

Analysis of 11-nor-?9 -tetrahydrocannabinol-9-carboxylic acid and its glucuronide in urine by capillary electrophoresis/mass spectrometry.  

PubMed

?(9) -Tetrahydrocannabinol is the primary psychoactive component in cannabis, one of the most commonly used illicit drugs in the world. This paper describes a simple and rapid method for direct analysis of major metabolites of ?(9) -tetrahydrocannabinol; 11-nor-?(9) -tetrahydrocannabinol-9-carboxylic acid and its glucuronide in urine by capillary electrophoresis/mass spectrometry. The only pretreatment needed for a urine sample was dilution with methanol containing an internal standard and centrifugation. Electrophoresis was carried out in an untreated fused-silica capillary (50 µm i.d. × 85 cm) filled with 40 m m ammonium formate (pH 6.4). An analysis could be completed within 10 min. For both compounds, the assay was linear over the range 0.1-10 µg/mL in urine with correlation coefficients (r(2) )?>0.99 and the limit of detection was 0.5 pg (10 nL injection). The detection yields and reproducibilities were determined at three different concentrations (0.1, 0.5 and 2 µg/mL in urine). The mean detection yields were 60-99%. The intra- and inter-day relative standard deviations of migration times were 0.063-0.19 and 0.18-0.36%, and those of peak areas were 4.2-18 and 5.9-25%, respectively. The proposed method successfully analyzed the urine samples of cannabis users. PMID:22419476

Iwamuro, Yoshiaki; Iio-Ishimaru, Reiko; Chinaka, Satoshi; Takayama, Nariaki; Hayakawa, Kazuichi

2012-11-01

195

In Vivo-Formed versus Preformed Metabolite Kinetics of trans-Resveratrol-3-sulfate and trans-Resveratrol-3-glucuronide  

PubMed Central

Metabolites in safety testing have gained a lot of attention recently. Regulatory agencies have suggested that the kinetics of preformed and in vivo-formed metabolites are comparable. This subject has been a topic of debate. We have compared the kinetics of in vivo-formed with preformed metabolites. trans-3,5,4?-Trihydroxystilbene [trans-resveratrol (RES)] and its two major metabolites, resveratrol-3-sulfate (R3S) and resveratrol-3-glucuronide (R3G) were used as model substrates. The pharmacokinetics (PK) of R3S and R3G were characterized under two situations. First, the pharmacokinetics of R3S and R3G were characterized (in vivo-formed metabolite) after administration of RES. Then, synthetic R3S and R3G were administered (preformed metabolite) and their pharmacokinetics were characterized. PK models were developed to describe the data. A three-compartment model for RES, a two-compartment model for R3S (preformed), and an enterohepatic cycling model for R3G (preformed) was found to describe the data well. These three models were further combined to build a comprehensive PK model, which was used to perform simulations to predict in vivo-formed metabolite kinetics. Comparisons were made between in vivo-formed and preformed metabolite kinetics. Marked differences were observed in the kinetics of preformed and in vivo-formed metabolites. PMID:22807110

Sharan, Satish; Iwuchukwu, Otito F.; Canney, Daniel J.; Zimmerman, Cheryl L.

2012-01-01

196

Reaction of iron pentacarbonyl with ethyl dichloroacetoacetate and dichloroacetylacetone  

SciTech Connect

This paper shows that ethyl dichloroacetoacetate and dichloroacetylacetone react with Fe(CO)/sub 5/ to form iron chelates Fe(CIC.(COR)COCH/sub 3/)/sub 3/. The structures of these chelates were elucidated by C1 35 NQR, mass and IR spectroscopy.

Velichko, F.K.; Abdulkina, Z.A.; Amriev, R.A.; Koznetsov, S.I.

1985-08-20

197

77 FR 12740 - Trinexapac-ethyl; Pesticide Tolerances  

Federal Register 2010, 2011, 2012, 2013

...unit could also be affected. The North American Industrial Classification System (NAICS...acute dietary assessment is protective of women that may become pregnant. ii. Chronic...established or proposed Codex, Canadian, or Mexican MRLs for trinexapac-ethyl in or on...

2012-03-02

198

Dissociation of the Ethyl Radical: An Exercise in Computational Chemistry  

ERIC Educational Resources Information Center

A set of exercises for use in a typical physical chemistry laboratory course are described, modeling the unimolecular dissociation of the ethyl radical to form ethylene and atomic hydrogen. Students analyze the computational results both qualitatively and quantitatively. Qualitative structural changes are compared to approximate predicted values…

Nassabeh, Nahal; Tran, Mark; Fleming, Patrick E.

2014-01-01

199

LC-MS/MS analysis of dextromethorphan metabolism in human saliva and urine to determine CYP2D6 phenotype and individual variability in N-demethylation and glucuronidation.  

PubMed

In order to establish a fast screening method for the determination of the CYP2D6 metabolic phenotype a sensitive LC-MS/MS assay to quantify dextromethorphan (DEX) and its O-demethylated metabolite dextrorphan (DOR) in human saliva was developed with limits of quantitation of 1 pmol/ml. Saliva was provided by 170 medical students 2h after oral ingestion of 30 mg (81 micromol) dextromethorphan hydrobromide. Individual ratios of the concentrations DEX/DOR (metabolic ratio, MR(DEX/DOR)) varied more than 25,000-fold (0.03-780). Two groups comprising 156 'Extensive' and 14 'Poor Metabolizers' were clearly distinguished. For the investigation of individual differences in N-demethylation and glucuronidation, four additional metabolites of DEX, 3-methoxymorphinan (MOM), 3-hydroxymorphinan (HOM), and the two O-glucuronides (DORGlu and HOMGlu) were measured by LC-MS/MS analysis of 6-h urine of 24 volunteers. The N-demethylation reactions DEX-to-MOM and DOR-to-HOM defined by the respective MR were significantly correlated. The same holds for the glucuronidation pathways (MR(DOR/DORGlu) versus MR(HOM/HOMGlu)). The three poor CYP2D6 metabolizers excreted relatively high amounts of the parent compound DEX (up to 7 micromol), but only low amounts of glucuronides (DORGlu: 0.4-1.0 micromol; HOMGlu: 0.2-0.7 micromol). For the 21 'Extensive Metabolizers', the two glucuronides were the most abundant, with relatively little interindividual variation (DORGlu: 10-44 micromol; HOMGlu: 5-17 micromol). For the excretion of the glucuronides, two normal distributions provided the best fit, indicating that the determination of the glucuronides alone could allow assignment of the CYP2D6 metabolic phenotype. PMID:15556536

Lutz, Ursula; Völkel, Wolfgang; Lutz, Roman W; Lutz, Werner K

2004-12-25

200

75 FR 17769 - In the Matter of Certain Products Advertised as Containing Creatine Ethyl Ester; Notice of...  

Federal Register 2010, 2011, 2012, 2013

...Certain Products Advertised as Containing Creatine Ethyl Ester; Notice of Commission Issuance...the Products Advertised as Containing Creatine Ethyl Ester of Respondents Found in Default...certain products advertised as containing creatine ethyl ester by reason of false...

2010-04-07

201

40 CFR 180.430 - Fenoxaprop-ethyl; tolerances for residues.  

Code of Federal Regulations, 2012 CFR

...General. Tolerances are established for residues of the herbicide fenoxaprop-ethyl, including its metabolites and...Time-limited tolerances are established for residues of the herbicide fenoxaprop-ethyl, including its...

2012-07-01

202

40 CFR 180.430 - Fenoxaprop-ethyl; tolerances for residues.  

Code of Federal Regulations, 2013 CFR

...General. Tolerances are established for residues of the herbicide fenoxaprop-ethyl, including its metabolites and...Time-limited tolerances are established for residues of the herbicide fenoxaprop-ethyl, including its...

2013-07-01

203

40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.  

Code of Federal Regulations, 2011 CFR

...General. (1) Tolerances are established for residues of the herbicide, flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5...01 (2) Tolerances are established for residues of the herbicide flufenpyr-ethyl; acetic acid,...

2011-07-01

204

40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.  

Code of Federal Regulations, 2012 CFR

...General. (1) Tolerances are established for residues of the herbicide, flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5...01 (2) Tolerances are established for residues of the herbicide flufenpyr-ethyl; acetic acid,...

2012-07-01

205

40 CFR 180.430 - Fenoxaprop-ethyl; tolerances for residues.  

Code of Federal Regulations, 2011 CFR

...General. Tolerances are established for residues of the herbicide fenoxaprop-ethyl, including its metabolites and...Time-limited tolerances are established for residues of the herbicide fenoxaprop-ethyl, including its...

2011-07-01

206

40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.  

Code of Federal Regulations, 2010 CFR

...General. (1) Tolerances are established for residues of the herbicide, flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5...01 (2) Tolerances are established for residues of the herbicide flufenpyr-ethyl; acetic acid,...

2010-07-01

207

40 CFR 180.595 - Flufenpyr-ethyl; tolerances for residues.  

Code of Federal Regulations, 2013 CFR

...General. (1) Tolerances are established for residues of the herbicide, flufenpyr-ethyl; acetic acid, [2-chloro-4-fluoro-5...01 (2) Tolerances are established for residues of the herbicide flufenpyr-ethyl; acetic acid,...

2013-07-01

208

Utility of coloured hair for the detection of drugs and alcohol.  

PubMed

The aim of this paper is to assess the utility of coloured hair for the detection of drugs and alcohol in a large statistically significant population. The positivity rate, the 1st, 5th, 50th, 95th, and 99th percentiles of five amphetamines, cannabinoids, cocaine, four opiates, methadone, buprenorphine, seven benzodiazepines, and ethyl glucuronide (EtG) in 9488 non-treated and 1026 cosmetically treated (dyed or bleached) authentic hair samples was compared. Analytical methods used were accredited for forensic purposes at the cut-offs defined by the German driving licence re-granting medical and psychological assessment (MPA) guidelines. Considering only the drug classes for which at least 10 positive samples were detected, the positivity rate in non-treated hair was highest for alcohol (4.50%; measured using EtG at concentrations ? 7 pg/mg hair), followed by THC (2.00%), cocaine (1.75%), and amphetamine (0.59%). While the 1st to 99th percentile range was significantly lower for drugs in treated, compared to non-treated hair, no significant change was observed for EtG. Additionally, no significant difference in the positivity rate was observed between treated hair and non-treated hair for both drugs and EtG. This study is the first attempt to evaluate the influence of cosmetic treatment, mainly dying, on the positivity rate for both drugs and EtG in hair samples submitted routinely for abstinence testing and the first to indicate that dyed and eventually bleached hair is not necessarily useless in detecting drugs and/or alcohol consumption, thus making coloured hair analysis still useful, often being the only possibility to prove such misuse. PMID:24817056

Agius, Ronald

2014-06-01

209

ForPeerReview New ethyl cellulose/acrylic hybrid latexes and coatings via  

E-print Network

ForPeerReview New ethyl cellulose/acrylic hybrid latexes and coatings via miniemulsion Article Keywords: Ethyl cellulose, Acrylic, Miniemulsion polymerization PeerReview 1 New ethyl cellulose/acrylic hybrid latexes and coatings via miniemulsion polymerization R. Chen,1

Boyer, Edmond

210

75 FR 82069 - Ethyl Alcohol for Fuel Use: Determination of the Base Quantity of Imports  

Federal Register 2010, 2011, 2012, 2013

...Investigation No. 332-288] Ethyl Alcohol for Fuel Use: Determination of the Base...U.S. domestic market for fuel ethyl alcohol during the 12-month period ending on...quantity'' of imports of fuel ethyl alcohol with a zero percent local feedstock...

2010-12-29

211

78 FR 9938 - Ethyl Alcohol for Fuel Use: Determination of the Base Quantity of Imports  

Federal Register 2010, 2011, 2012, 2013

...Investigation No. 332-288] Ethyl Alcohol for Fuel Use: Determination of the Base...U.S. domestic market for fuel ethyl alcohol during the 12-month period ending on...quantity'' of imports of fuel ethyl alcohol, and the Commission transmitted it...

2013-02-12

212

76 FR 82320 - Ethyl Alcohol for Fuel Use: Determination of the Base Quantity of Imports  

Federal Register 2010, 2011, 2012, 2013

...Investigation No. 332-288] Ethyl Alcohol for Fuel Use: Determination of the Base...U.S. domestic market for fuel ethyl alcohol during the 12-month period ending on...quantity'' of imports of fuel ethyl alcohol with a zero percent local feedstock...

2011-12-30

213

Associations between polymorphisms in glucuronidation and sulfation enzymes and mammographic breast density in premenopausal women in the United States  

PubMed Central

Objective Sex hormones are metabolized to less active compounds via (i) glucuronidation, catalyzed by UDP-glucuronosyltransferases (UGT) and (ii) sulfation, catalyzed by sulfotransferases (SULT). Functional UGT and SULT polymorphisms can affect clearance of sex hormones, thereby influencing exposure in hormone-sensitive tissues, such as the breast. We assessed relationships between functional polymorphisms in the UGT and SULT genes and breast density in premenopausal women. Methods One-hundred and seventy five women ages 40–45 years, who had a screening mammogram taken within the previous year, provided a genomic DNA sample. Mammograms were digitized to obtain breast density measures. Using generalized linear regression, we assessed associations between percent breast density and polymorphisms in the UGT1A and UGT2B families, SULT1A1, and SULT1E1. Results Women with the SULT1A1(H213/H213) genotype had 16% lower percent breast density compared to women with the SULT1A1(R213/R213) genotype after controlling for ethnicity (p-value = 0.001). Breast density was 5% lower among women carrying at least one copy of the UGT1A1(TA7)-UG1A3(R11)-UGT1A3(A47) haplotype compared to the UGT1A1(TA6)-UG1A3(W11)-UGT1A3(V47) haplotype (p-value = 0.07). No associations were observed between polymorphisms in the UGT2B family or SULT1E1 and breast density. Conclusion Polymorphisms in SULT1A1 and the UGT1A locus may influence percent breast density in premenopausal women. PMID:20142249

Yong, Mellissa; Schwartz, Stephen M.; Atkinson, Charlotte; Makar, Karen W.; Thomas, Sushma S.; Newton, Katherine M.; Aiello Bowles, Erin J.; Holt, Victoria L.; Leisenring, Wendy M.; Lampe, Johanna W.

2009-01-01

214

Associations between polymorphisms in glucuronidation and sulfation enzymes and sex steroid concentrations in premenopausal women in the United States  

PubMed Central

Glucuronidation, catalyzed by UDP-glucuronosyltransferases (UGT) and sulfation, catalyzed by sulfotransferases (SULT), are pathways through which sex steroids are metabolized to less active compounds. These enzymes are highly polymorphic and genetic variants frequently result in higher or lower activity. The phenotypic effects of these polymorphisms on circulating sex steroids in premenopausal women have not yet been investigated. One hundred and seventy women ages 40-45 years had a blood sample drawn during the follicular phase of the menstrual cycle for sex steroid measures and to obtain genomic DNA. Urine was collected for 2-hydroxy (OH) estrone (E1) and 16?-OH E1 measures. Generalized linear regression models were used to assess associations between sex steroids and polymorphisms in the UGT1A and UGT2B families, SULT1A1, and SULT1E1. Women with the UGT1A1(TA7/TA7) genotype had 25% lower mean estradiol (E2) concentrations compared to the wildtype (TA6/TA6) (p = 0.02). Similar associations were observed between SULT1A1(R213/H213) and E1 (13% lower mean E1 concentration vs. wildtype; p-value = 0.02) and UGT2B4(E458/E458) and dehydroepiandrosterone (DHEA) (20% lower mean DHEA vs. wildtype; p-value = 0.03). The SULT1E1(A/C) and the UGT1A1(TA7)-UGT1A3(R11) haplotypes were associated with reduced estrogen concentrations. Further study of UGT and SULT polymorphisms and circulating sex steroid measures in larger populations of premenopausal women is warranted. PMID:21193038

Yong, Mellissa; Schwartz, Stephen M.; Atkinson, Charlotte; Makar, Karen W.; Thomas, Sushma S.; Stanczyk, Frank Z.; Westerlind, Kim C.; Newton, Katherine M.; Holt, Victoria L.; Leisenring, Wendy M.; Lampe, Johanna W.

2011-01-01

215

Quantitative determination of free and total bisphenol A in human urine using labeled BPA glucuronide and isotope dilution mass spectrometry.  

PubMed

Bisphenol A (BPA) is a widely used industrial chemical in the manufacturing of polycarbonate plastic bottles, food and beverage can linings, thermal receipts, and dental sealants. Animal and human studies suggest that BPA may disrupt normal hormonal function and hence, potentially, have negative effects on the human health. While total BPA is frequently reported, it is recognized that free BPA is the biologically active form and is rarely reported in the literature. The objective of this study was to develop a sensitive and improved method for the measurement of free and total BPA in human urine. Use of a labeled conjugated BPA (bisphenol A-d6 ?-D-glucuronide) allowed for the optimization of the enzymatic reaction and permitted an accurate determination of the conjugated BPA concentration in urine samples. In addition, a (13)C12-BPA internal standard was used to account for the analytical recoveries and performance of the isotope dilution method. Solid-phase extraction (SPE) combined with derivatization and analysis using a triple quadrupole GC-EI/MS/MS system achieved very low method detection limit of 0.027 ng/mL. BPA concentrations were measured in urine samples collected during the second and third trimesters of pregnancy in 36 Canadian women. Total maternal BPA concentrations in urine samples ranged from not detected to 9.40 ng/mL (median, 1.21 ng/mL), and free BPA concentrations ranged from not detected to 0.950 ng/mL (median, 0.185 ng/mL). Eighty-six percent of the women had detectable levels of conjugated BPA, whereas only 22 % had detectable levels of free BPA in their urine. BPA levels measured in this study agreed well with data reported internationally. PMID:24817354

Kubwabo, Cariton; Kosarac, Ivana; Lalonde, Kaela; Foster, Warren G

2014-07-01

216

Rapid deconjugation of SN-38 glucuronide and adsorption of released free SN-38 by intestinal microorganisms in rat  

PubMed Central

One of the dose-limiting toxicities of irinotecan hydrochloride (CPT-11) is delayed-onset diarrhea. CPT-11 is converted to its active metabolite, SN-38, which is conjugated to SN-38 glucuronide (SN-38G). SN-38G excreted in the intestinal lumen is extensively deconjugated by bacterial ?-glucuronidase, resulting in the regeneration of SN-38, which causes diarrhea. However, the deconjugation of SN-38G by the intestinal microflora remains to be clarified. This study aimed to investigate the microbial transformation of SN-38G by an anaerobic mixed culture of rat cecal microorganisms. Concentrations of SN-38G and SN-38 were then determined using high-performance liquid chromatography. Complete deconjugation of SN-38G to SN-38 in the mixed cultures was observed within 1 h of incubation, with 62.7% of the added SN-38G being found in the supernatant. Approximately 80.4% of the SN-38 in the supernatant was bound to protein, and the remaining 19.6% was detected as active free SN-38. In total, only 12.3% (19.6 × 62.7%) of the SN-38G added to the test tube was found in the supernatant in the ultrafiltrable free form, indicating that approximately 90% of the SN-38G added to the growth medium either remained adsorbed onto the pelleted fraction or occurred in a protein-bound form in the supernatant. The remaining 10% of the SN-38G added to the growth medium existed in the unbound form, the form capable of causing damage to the intestinal membrane. In conclusion, these results indicated that the greater part of the SN-38 produced from SN-38G by the action of bacterial ?-glucuronidase is rapidly adsorbed onto intestinal bacterial cell walls or dietary fibers in pelleted fraction, and only 10% remains in the ultrafiltrable unbound form in the intestinal luminal fluid. PMID:22740943

TAKAKURA, AKIRA; KURITA, AKINOBU; ASAHARA, TAKASHI; YOKOBA, MASANORI; YAMAMOTO, MICHIKO; RYUGE, SHINICHIRO; IGAWA, SATOSHI; YASUZAWA, YUKITOSHI; SASAKI, JIICHIRO; KOBAYASHI, HIROSUKE; MASUDA, NORIYUKI

2011-01-01

217

Glucuronidation does not suppress the estrogenic activity of quercetin in yeast and human breast cancer cell model systems.  

PubMed

Several plant-derived molecules, referred to as phytoestrogens, are thought to mimic the actions of endogenous estrogens. Among these, quercetin, one of the most widespread flavonoids in the plant kingdom, has been reported as estrogenic in some occasions. However, quercetin occurs in substantial amounts as glycosides such as quercetin-3-O-glucoside (isoquercitrin) and quercetin-3-O-rutinoside (rutin) in dietary sources. It is now well established that quercetin undergoes substantial phase II metabolism after ingestion by humans, with plasma metabolites after a normal dietary intake rarely exceeding nmol/L concentrations. Therefore, attributing phytoestrogenic activity to flavonoids without taking into account the fact that it is their phase II metabolites that enter the circulatory system, will almost certainly lead to misleading conclusions. With the aim of clarifying the above issue, the goal of the present study was to determine if plant-associated quercetin glycosides and human phase II quercetin metabolites, actually found in human biological fluids after intake of quercetin containing foods, are capable of interacting with the estrogen receptors (ER). To this end, we used a yeast-based two-hybrid system and an estrogen response element-luciferase reporter assay in an ER-positive human cell line (MCF-7) to probe the ER interaction capacities of quercetin and its derivatives. Our results show that quercetin-3-O-glucuronide, one of the main human phase II metabolites produced after intake of dietary quercetin, displays ER?- and ER?-dependent estrogenic activity, the functional consequences of which might be related to the protective activity of diets rich in quercetin glycosides. PMID:24657077

Ruotolo, Roberta; Calani, Luca; Brighenti, Furio; Crozier, Alan; Ottonello, Simone; Del Rio, Daniele

2014-10-01

218

Identification of an antioxidant, ethyl protocatechuate, in peanut seed testa.  

PubMed

The antioxidant activity and identification of the antioxidant component of peanut seed testa were investigated. The antioxidant activity of peanut seed testa was studied in the linoleic acid model system by using the ferric thiocyanate method. Among the five organic solvent extracts, the ethanolic extracts of peanut seed testa (EEPST) produced higher yields and stronger antioxidant activity than other organic solvent extracts. EEPST was separated into 17 fractions on silica gel column chromatography. Fraction 17, which showed the largest yield and significant antioxidant activity, was separated by thin-layer chromatography. Four major antioxidative subfractions were present. Subfraction 17-2 was found to be effective in preventing oxidation of linoleic acid. This subfraction was further fractionated and isolated and characterized by UV, MS, IR, and (1)H NMR techniques. The active compound was identified as ethyl protocatechuate (3,4-dihydroxybenzoic acid ethyl ester). PMID:12670184

Huang, Shiow Chyn; Yen, Gow-Chin; Chang, Lee-Wen; Yen, Wen-Jye; Duh, Pin-Der

2003-04-01

219

Icosapent ethyl for the treatment of severe hypertriglyceridemia  

PubMed Central

Hypertriglyceridemia is a highly prevalent lipid abnormality and it is associated with atherosclerosis, with a growing body of evidence linking elevated triglycerides (TGs) with cardiovascular disease. The current major omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA) combination, lowers serum TGs while often increasing levels of low-density lipoprotein cholesterol. Icosapent ethyl is an omega-3 polyunsaturated fatty acid with a 96% pure ethyl ester of EPA that has been recently approved for lowering TG levels in patients with very high TGs (?500 mg/dL), and it does so without significantly affecting serum low-density lipoprotein cholesterol. The potential benefits of omega-3 fatty acid therapy for dyslipidemias will be discussed, including the potential pros and cons of EPA alone versus the more common and readily available EPA/DHA combination therapy. PMID:25028554

Fares, Hassan; Lavie, Carl J; DiNicolantonio, James J; O'Keefe, James H; Milani, Richard V

2014-01-01

220

Synthesis and degradation behavior of poly(ethyl cyanoacrylate)  

Microsoft Academic Search

Poly(ethyl cyanoacrylate) was synthesized using N,N?-dimethyl-p-toluidine as an initiator through an anionic\\/zwitterionic pathway. The degradability and the degradation mechanism of the prepared polymer were examined from various viewpoints. A combination of TGA and GPC analysis allowed us to confirm that the thermal degradation of this polymer was predominantly due to an unzipping depolymerization process initiated from the polymer chain terminus.

Moon Gyu Han; Sanghoon Kim; Sean X. Liu

2008-01-01

221

Kinetic and J-resolved statistical total correlation NMR spectroscopy approaches to structural information recovery in complex reacting mixtures: application to acyl glucuronide intramolecular transacylation reactions.  

PubMed

We demonstrate here a new variant on a statistical spectroscopic method for recovering structural information on unstable intermediates formed in reaction mixtures. We exemplify this approach with respect to the internal acyl migration reactions of 1-beta-O-acyl glucuronides (AGs), which rearrange at neutral or slightly alkaline pH on a minute to hour time scale to yield a series of positional glucuronide ring isomers and alpha/beta anomers from the 1-beta (starting material), i.e. 2-beta, 2-alpha, 1-alpha, 3-beta, 3-alpha, and 4-beta, 4-alpha isomers together with the aglycon and alpha- and beta-glucuronic acid hydrolysis products. Multiple sequential 800 MHz cryoprobe (1)H NMR spectra (1D and 2D J-resolved, JRES) were collected on a 5.1 mM solution of a synthetic model drug glucuronide, 1-beta-O-acyl (S)-alpha-methyl phenylacetyl glucuronide (MPG) in 0.1 M sodium phosphate buffer in D2O at pD 7.4 over 18 h to monitor the reaction which leads to the formation of the eight positional isomers and hydrolysis products. As the reaction proceeds and new isomers form, the NMR signal intensities vary accordingly allowing the application of a novel kinetic variant on statistical total correlation spectroscopy (K-STOCSY) method to recover the connectivities between proton signals on the same reacting molecule based on their intensity covariance through time. We performed K-STOCSY analysis on both the standard 1D NMR spectra and the skyline projected singlets of the (1)H-(1)H JRES NMR spectra through time, i.e. the K-JRES-STOCSY experimental variant, which increases the effective spectral dispersion and is ideally suited for the analysis of heavily overlapped spin systems. High statistical correlations were observed between mutarotated alpha- and beta-anomers of individual positional isomers, as well as directly acyl migrated products and anticorrelation observed between signals from compounds that were being depleted as others increased, e.g. between the 1-beta and 2-alpha/2-beta isomers. This statistical kinetic approach enabled the recovery of structural connectivity information on all isomers allowing unequivocal resonance assignment, and this approach to spectroscopic information recovery has wider potential uses in the study of reactions that occur on the second-to-minute time scale in conditions where multiple sequential NMR spectra can be collected. JRES-STOCSY is also of potential use as a method for recovering spectroscopic information in highly overlapped NMR signals and spin systems in other types of complex mixture analysis. PMID:18470997

Johnson, Caroline H; Athersuch, Toby J; Wilson, Ian D; Iddon, Lisa; Meng, Xiaoli; Stachulski, Andrew V; Lindon, John C; Nicholson, Jeremy K

2008-07-01

222

Sensory reception of the primer pheromone ethyl oleate  

NASA Astrophysics Data System (ADS)

Social work force distribution in honeybee colonies critically depends on subtle adjustments of an age-related polyethism. Pheromones play a crucial role in adjusting physiological and behavioral maturation of nurse bees to foragers. In addition to primer effects of brood pheromone and queen mandibular pheromone—both were shown to influence onset of foraging—direct worker-worker interactions influence adult behavioral maturation. These interactions were narrowed down to the primer pheromone ethyl oleate, which is present at high concentrations in foragers, almost absent in young bees and was shown to delay the onset of foraging. Based on chemical analyses, physiological recordings from the antenna (electroantennograms) and the antennal lobe (calcium imaging), and behavioral assays (associative conditioning of the proboscis extension response), we present evidence that ethyl oleate is most abundant on the cuticle, received by olfactory receptors on the antenna, processed in glomeruli of the antennal lobe, and learned in olfactory centers of the brain. The results are highly suggestive that the primer pheromone ethyl oleate is transmitted and perceived between individuals via olfaction at close range.

Muenz, Thomas S.; Maisonnasse, Alban; Plettner, Erika; Le Conte, Yves; Rössler, Wolfgang

2012-05-01

223

Ethyl arachidonate is the predominant fatty acid ethyl ester in the brains of alcohol-intoxicated subjects at autopsy  

Microsoft Academic Search

The role of fatty acid ethyl esters (FAEE), the nonoxidative ethanol metabolites, as mediators of alcohol-induced organ damage\\u000a is increasingly being recognized. FAEE are detectable in the blood and in liver and adipose tissue after ethanol ingestion,\\u000a and on that basis, FAEE can be used as markers of ethanol intake. In this study, 10 samples of human brain were collected

M. A. Refaai; P. N. Nguyen; J. E. Cluette-Brown; M. Laposata

2003-01-01

224

Distribution and organoleptic impact of ethyl 2-methylbutanoate enantiomers in wine.  

PubMed

The enantiomers of ethyl 2-methylbutanoate were assayed in several wines using chiral gas chromatography (?-cyclodextrin). Analyses of 37 commercial red wines from various vintages and origins revealed the almost exclusive presence of the S-enantiomeric form. The average concentration was ?50 ?g/L, but the oldest samples were found to contain higher ethyl 2-methylbutanoate levels than the youngest wines. The olfactory threshold of a racemic mixture of ethyl (2R)-2-methylbutanoate and ethyl (2S)-2-methylbutanoate (50:50, m/m) in dilute alcohol solution was 2.60 ?g/L, almost twice that of the S-form, which was 1.53 ?g/L. Ethyl (2S)-2-methylbutanoate and the racemic mixture of ethyl (2R)-2-methylbutanoate and ethyl (2S)-2-methylbutanoate had different aromatic nuances: the former was mainly defined by fruity descriptors, such as green apple (Granny Smith) and strawberry, whereas the latter had an unspecific, caustic, fruity, solvent odor. Sensory analysis revealed an enhancing effect of ethyl (2S)-2-methylbutanoate on the perception of fruity aromas in the matrices studied: the "olfactory threshold" of the fruity pool, consisting of esters found in red wines, in dilute alcohol solution alone was higher than that of the same mixture supplemented with 50 ?g/L ethyl (2S)-2-methylbutanoate. The sensory profiles of these aromatic reconstitutions highlighted the contribution of ethyl (2S)-2-methylbutanoate to black-berry-fruit descriptors. PMID:24844693

Lytra, Georgia; Tempere, Sophie; de Revel, Gilles; Barbe, Jean-Christophe

2014-06-01

225

Impact of trans-resveratrol-sulfates and -glucuronides on endothelial nitric oxide synthase activity, nitric oxide release and intracellular reactive oxygen species.  

PubMed

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a polyphenolic natural product mainly present in grape skin, berries and peanuts. In the vasculature resveratrol is thought to boost endothelial function by increasing endothelial nitric oxide synthase (eNOS) expression, by enhancing eNOS activity, and by reduction of reactive oxygen species (ROS) levels. Recent studies show that dietary resveratrol is metabolized in the liver and intestine into resveratrol-sulfate and -glucuronide derivatives questioning the relevance of multiple reported mechanistic in vitro data on resveratrol. In this study, we compare side by side different physiologically relevant resveratrol metabolites (resveratrol sulfates- and -glucuronides) and their parent compound in their influence on eNOS enzyme activity, endothelial NO release, and intracellular ROS levels. In contrast to resveratrol, none of the tested resveratrol metabolites elevated eNOS enzyme activity and endothelial NO release or affected intracellular ROS levels, leaving the possibility that not tested metabolites are active and able to explain in vivo findings. PMID:25329867

Ladurner, Angela; Schachner, Daniel; Schueller, Katharina; Pignitter, Marc; Heiss, Elke H; Somoza, Veronika; Dirsch, Verena M

2014-01-01

226

Hepatic disposition and biliary excretion of bilirubin and bilirubin glucuronides in intact rats. Differential processing of pigments derived from intra- and extrahepatic sources.  

PubMed Central

Mechanisms for transport of bilirubin and its conjugates in hepatocytes have not been defined. We investigated the hepatic processing of bilirubin glucuronides and their precursors, and characterized the disposition of bile pigments arising from intraversus extrahepatic sources. Tracer doses of purified radiolabeled biliverdin, bilirubin, bilirubin monoglucuronide (BMG) or diglucuronide (BDG) were administered intravenously to intact normal or jaundiced homozygous Gunn rats. Rapid sequential analysis of radiolabeled BMG and BDG in bile revealed comparable excretion patterns following biliverdin and bilirubin injection, with BDG as the major pigment. Biliary excretion of radiolabeled conjugates from injected BMG was more rapid, with BMG predominating. Excretion of injected BDG in normal rats and BMG or BDG in Gunn rats was virtually identical to that of unaltered BMG in normal rats. Model independent analysis by deconvolution provided objective comparison of the disposition of radiolabeled pigments from the different sources. These findings indicate that bilirubin glucuronides formed in the liver from endogenous (hepatic) and exogenous (extrahepatic) sources of bilirubin follow a similar excretory pathway. BMG formed endogenously is converted preferentially to BDG, whereas circulating BMG is excreted predominantly unchanged. Exogenous conjugated bilirubins are excreted more rapidly than those generated intrahepatically, by a transcellular pathway that is largely independent of the conjugation system. PMID:3558820

Crawford, J M; Ransil, B J; Potter, C S; Westmoreland, S V; Gollan, J L

1987-01-01

227

Synthesis and application of resorufin ?-D-glucuronide, a low-cost chromogenic substrate for detecting Escherichia coli in drinking water.  

PubMed

The development of low-cost tests for Escherichia coli is hampered by the expense and limited choice of enzyme substrates. Most chromogenic substrates are required in costly amounts, while fluorogenic substrates require an additional apparatus (e.g., an ultraviolet lamp) to be detected. Herein, we propose an alternative chromogenic substrate, resorufin ?-d-glucuronide (REG), which is exceptionally sensitive and may be employed in very small amounts. We show that REG can be produced similarly to other simple glucuronides and should therefore be no more expensive. The compound is used by both healthy and injured E. coli, resulting in a pronounced color change from orange to a bright pink. Because the released dye (resorufin) has a high extinction coefficient, substantially lower amounts are needed than for commercially available substrates. The potential of this substrate is demonstrated by a presence/absence test requiring just 0.1 mg of REG/100 mL of water sample, one hundredth of the quantity needed for common chromogenic substrates, with an estimated bulk cost of ?0.1 U.S. cents/test. REG shows promise as a chromogenic substrate for E. coli detection and should be considered in the development of new water tests, especially for low-income settings. PMID:25035967

Magro, Germinal; Bain, Robert E S; Woodall, Claire A; Matthews, Robert L; Gundry, Stephen W; Davis, Anthony P

2014-08-19

228

Direct determination of diazepam and its glucuronide metabolites in human whole blood by ?Elution solid-phase extraction and liquid chromatography-tandem mass spectrometry.  

PubMed

A ?Elution solid-phase extraction (SPE) liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous determination of diazepam, nordiazepam, oxazepam, oxazepam glucuronide, temazepam and temazepam glucuronide in human whole blood is presented. 200 ?L of whole blood samples were loaded onto a Waters Oasis HLB 96-well ?Elution SPE plate using 75 ?L of methanol as the elution solvent, and the eluents were injected into an Eclipse XDB C18 column. No hydrolysis, solvent transfer, evaporation or reconstitution was involved in the sample preparation procedures. Tandem mass spectrometric detection with Turbo Ion Spray was conducted via multiple reaction monitoring (MRM) under positive ionization mode. The method was validated and proved to be accurate (accuracy within 93-108%), precise (intra-day RSD<9.9% and inter-day RSD<7.2%) and sensitive with limits of detection (LOD) in the range of 0.05-0.25 ng/mL for all the compounds. Extraction recoveries were in the range of 31-80% for all the analytes. This method demonstrated to be reproducible and reliable. The applicability of the method was demonstrated by analysis of several forensic cases involving diazepam and its metabolites. PMID:24314534

Wang, Rong; Wang, Xin; Liang, Chen; Ni, Chunfang; Xiong, Lingjuan; Rao, Yulan; Zhang, Yurong

2013-12-10

229

Development of a simple analytical method for the simultaneous determination of paracetamol, paracetamol-glucuronide and p-aminophenol in river water.  

PubMed

Paracetamol is among the most worldwide consumed pharmaceuticals. Although its occurrence in the environment is well documented, data about the presence of its metabolites and transformation products is very scarce. The present work describes the development of an analytical method for the simultaneous determination of paracetamol, its principal metabolite (paracetamol-glucuronide) and its main transformation product (p-aminophenol) based on solid phase extraction (SPE) and high performance liquid chromatography coupled to diode array detection (HPLC-DAD). The method was applied to analysis of river waters, showing to be suitable to be used in routine analysis. Different SPE sorbents were compared and the use of two Oasis WAX cartridges in tandem proved to be the most adequate approach for sample clean up and pre-concentration. Under optimized conditions, limits of detection in the range 40-67ng/L were obtained, as well as mean recoveries between 60 and 110% with relative standard deviations (RSD) below 6%. Finally, the developed SPE-HPLC/DAD method was successfully applied to the analysis of the selected compounds in samples from seven rivers located in the north of Portugal. Nevertheless all the compounds were detected, it was the first time that paracetamol-glucuronide was found in river water at concentrations up to 3.57?g/L. PMID:23727870

Santos, Lúcia H M L M; Paíga, Paula; Araújo, Alberto N; Pena, Angelina; Delerue-Matos, Cristina; Montenegro, M Conceição B S M

2013-07-01

230

Morphine-6?-glucuronide has a higher efficacy than morphine as a mu-opioid receptor agonist in the rat locus coeruleus  

PubMed Central

The pharmacological properties of the active morphine metabolite, morphine-6?-D-glucuronide (M6G), and the parent compound were compared in rat locus coeruleus neurons by electrophysiological recording in brain slices.M6G and morphine activated potassium currents in voltage clamped neurons, which were blocked by the opioid receptor antagonist naloxone.Both M6G and morphine behaved as partial agonists that produced maximal responses smaller than the system maximum, which was measured using [Met5]-enkephalin. M6G produced a larger maximal response (78%) than morphine (62%), which we estimated was due to a 2–4 fold difference in the relative efficacy of the agonists.3-O-methoxynaltrexone, which has been reported to behave as a selective antagonist of a M6G preferring receptor, was equally effective at blocking currents produced by M6G and the selective mu-opioid receptor agonist DAMGO.M6G currents were occluded by a prior application of morphine, and were reduced when mu-opioid receptors were desensitized by using [Met5]-enkephalin.Morphine-3?-D-glucuronide did not affect action potential firing or membrane currents in locus coeruleus neurons and had no effect on currents produced by M6G.These results show that the relative efficacy of M6G is higher than morphine in locus coeruleus neurons, contrary to what has been shown using mu-opioid receptors expressed in cell clones. PMID:11090116

Osborne, Peregrine B; Chieng, Billy; Christie, MacDonald J

2000-01-01

231

Effect of Chlorimuron-Ethyl on Biochemical Mechanism in Tolerant Sugar Beet  

Microsoft Academic Search

Effect of chlorimuron-ethyl on biochemical mechanism in tolerant sugar beet was investigated to provide basic data on using the tolerant genotype properly. Tolerant sugar beet was used to analyze its biochemical mechanism under chlorimuron-ethyl stress with frame culture in field and water culture. Glutathione S-transferase (GST) activity of leaves in tolerant sugar beet was remarkably increased as chlorimuron-ethyl was preemergence

Wei DING; Feng-ming MA; Zhuo CHENG; Bo TAO

2010-01-01

232

Glucuronidation and Methylation of Procyanidin Dimers B2 and 3,3’’-Di-O-Galloyl-B2 and Corresponding Monomers Epicatechin and 3-O-Galloyl-Epicatechin in Mouse Liver  

PubMed Central

Purpose The 3,3’’-di-O-galloyl ester of procyanidin B2 (B2G2) is a component of grape seed extract that inhibits growth of human prostate carcinoma cell lines. In preparation for studies in mice, its hepatic metabolism was examined in vitro and compared to B2 and the corresponding monomers, epicatechin (EC) and 3-O-galloyl-epicatechin (ECG). Methods Compounds were incubated with liver microsomes or cytosol containing cofactors for glucuronidation, sulfation or methylation, and products analyzed by liquid chromatography-mass spectrometry (LC-MS). B2G2 was administered orally to mice and plasma analyzed by LC-MS for unmodified procyanidin and metabolites. Results Glucuronides and methyl ethers of B2 and B2G2 were formed in small amounts. In contrast, EC and ECG were largely or completely converted to glucuronides, sulfates and methyl ethers under the same incubation conditions. B2G2 given orally to mice was partially absorbed intact; no significant metabolites were detected in plasma. Conclusions Glucuronidation and methylation of procyanidins B2 and B2G2 occurred but were minor processes in vitro. B2G2 was partially absorbed intact in mice after oral dosing and did not undergo significant metabolism. Unlike the flavanol monomers EC and ECG, therefore, B2G2 bioavailability should not be limited by metabolism. These results paved the way for ongoing pharmacokinetic and efficacy studies. PMID:22068277

Shrestha, Suraj P.; Thompson, John A.; Wempe, Michael F.; Gu, Mallikarjuna; Agarwal, Rajesh; Agarwal, Chapla

2012-01-01

233

DISCOVERY OF METHYL ACETATE AND GAUCHE ETHYL FORMATE IN ORION  

SciTech Connect

We report on the discovery of methyl acetate, CH{sub 3}COOCH{sub 3}, through the detection of a large number of rotational lines from each one of the spin states of the molecule: AA species (A{sub 1} or A{sub 2}), EA species (E{sub 1}), AE species (E{sub 2}), and EE species (E{sub 3} or E{sub 4}). We also report, for the first time in space, the detection of the gauche conformer of ethyl formate, CH{sub 3}CH{sub 2}OCOH, in the same source. The trans conformer is also detected for the first time outside the Galactic center source SgrB2. From the derived velocity of the emission of methyl acetate, we conclude that it arises mainly from the compact ridge region with a total column density of (4.2 {+-} 0.5) Multiplication-Sign 10{sup 15} cm{sup -2}. The derived rotational temperature is 150 K. The column density for each conformer of ethyl formate, trans and gauche, is (4.5 {+-} 1.0) Multiplication-Sign 10{sup 14} cm{sup -2}. Their abundance ratio indicates a kinetic temperature of 135 K for the emitting gas and suggests that gas-phase reactions could participate efficiently in the formation of both conformers in addition to cold ice mantle reactions on the surface of dust grains.

Tercero, B.; Cernicharo, J.; Lopez, A.; Caro, G. M. Munoz [Department of Astrophysics, CAB, INTA-CSIC, Crta Torrejon-Ajalvir, km. 4, E-28850 Torrejon de Ardoz, Madrid (Spain); Kleiner, I.; Nguyen, H. V. L., E-mail: terceromb@cab.inta-csic.es, E-mail: jcernicharo@cab.inta-csic.es, E-mail: lopezja@cab.inta-csic.es, E-mail: munozcg@cab.inta-csic.es, E-mail: isabelle.kleiner@lisa.u-pec.fr, E-mail: nguyen@pc.rwth-aachen.de [Laboratoire Interuniversitaire des Systemes Atmospheriques, CNRS/IPSL UMR7583 et Universites Paris Diderot et Paris Est, 61 av. General de Gaulle, F-94010 Creteil (France)

2013-06-10

234

Transesterification process to manufacture ethyl ester of rape oil  

SciTech Connect

A process for the production of the ethyl ester of winter rape [EEWR] for use as a biodiesel fuel has been studied. The essential part of the process is the transesterification of rape oil with ethanol, in the presence of a catalyst, to yield the ethyl ester of rape oil as a product and glycerin as a by-product. Experiments have been performed to determine the optimum conditions for the preparation of EEWR. The process variables were: (1) temperature, (2) catalyst, (3) rate of agitation, (4) water content of the alcohol used, and (5) the amount of excess alcohol used. The optimum conditions were: (1) room temperature, (2) 0.5% sodium methoxide or 1% potassium hydroxide catalyst by weight of rapeseed oil, (3) extremely vigorous agitation with some splashing during the initial phase of the reaction and agitation was not necessary after the reaction mixture became homogeneous, (4) absolute ethanol was necessary for high conversion, and (5) 50% excess ethanol with NaOCH{sub 3} or 100% excess with KOH gave a maximum conversion. Viscosity, cloud point and pour point of the EEWR were measured. A preliminary break-even cost for the commercial production of EEWR was found to be $0.55/liter [$2.08/US gallon].

Korus, R.A.; Hoffman, D.S.; Bam, N.; Peterson, C.L.; Drown, D.C. [Univ. of Idaho, Moscow, ID (United States)

1993-12-31

235

Discovery of Methyl Acetate and Gauche Ethyl Formate in Orion  

NASA Astrophysics Data System (ADS)

We report on the discovery of methyl acetate, CH3COOCH3, through the detection of a large number of rotational lines from each one of the spin states of the molecule: AA species (A1 or A2), EA species (E1), AE species (E2), and EE species (E3 or E4). We also report, for the first time in space, the detection of the gauche conformer of ethyl formate, CH3CH2OCOH, in the same source. The trans conformer is also detected for the first time outside the Galactic center source SgrB2. From the derived velocity of the emission of methyl acetate, we conclude that it arises mainly from the compact ridge region with a total column density of (4.2 ± 0.5) × 1015 cm-2. The derived rotational temperature is 150 K. The column density for each conformer of ethyl formate, trans and gauche, is (4.5 ± 1.0) × 1014 cm-2. Their abundance ratio indicates a kinetic temperature of 135 K for the emitting gas and suggests that gas-phase reactions could participate efficiently in the formation of both conformers in addition to cold ice mantle reactions on the surface of dust grains. This work was based on observations carried out with the IRAM 30 m telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).

Tercero, B.; Kleiner, I.; Cernicharo, J.; Nguyen, H. V. L.; López, A.; Muñoz Caro, G. M.

2013-06-01

236

Polychlorinated biphenyl congeners that increase the glucuronidation and biliary excretion of thyroxine are distinct from the congeners that enhance the serum disappearance of thyroxine.  

PubMed

Polychlorinated biphenyl (PCB) congeners differentially reduce serum thyroxine (T(4)) in rats, but little is known about their ability to affect biliary excretion of T(4). Thus, male Sprague-Dawley rats were orally administered Aroclor-1254, Aroclor-1242 (32 mg/kg per day), PCB-95, PCB-99, PCB-118 (16 mg/kg per day), PCB-126 (40 ?g/kg per day), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (3.9 ?g/kg per day), or corn oil for 7 days. Twenty-four hours after the last dose, [(125)I]T(4) was administered intravenously, and blood, bile, and urine samples were collected for quantifying [(125)I]T(4) and in bile [(125)I]T(4) metabolites. Serum T(4) concentrations were reduced by all treatments, but dramatic reductions occurred in response to Aroclor-1254, PCB-99 [phenobarbital (PB)-type congener], and PCB-118 (mixed-type congener). None of the treatments increased urinary excretion of [(125)I]T(4). Aroclor-1254, PCB-118, TCDD, and PCB-126 (TCDD-type congener) increased biliary excretion of T(4)-glucuronide by 850, 756, 710, and 573%, respectively, corresponding to marked induction of hepatic UDP-glucuronosyltransferase (UGT) activity toward T(4). PCB-95 and PCB-99 did not induce UGT activity; therefore, the increased biliary excretion of T(4)-glucuronide was related to the affinity of congeners for the aryl hydrocarbon receptor. The disappearance of [(125)I]T(4) from serum was rapid (within 15-min) and was increased by Aroclor-1254, PCB-99 and PCB-118. Thus, reductions in serum T(4) in response to PCBs did not always correspond with UGT activity toward T(4) or with increased biliary excretion of T(4)-glucuronide. The rapid disappearance of [(125)I]T(4) from the serum of rats treated with PB-like PCBs suggests that increased tissue uptake of T(4) is an additional mechanism by which PCBs may reduce serum T(4). PMID:22187485

Martin, L A; Wilson, D T; Reuhl, K R; Gallo, M A; Klaassen, C D

2012-03-01

237

Polychlorinated Biphenyl Congeners that Increase the Glucuronidation and Biliary Excretion of Thyroxine Are Distinct from the Congeners that Enhance the Serum Disappearance of Thyroxine  

PubMed Central

Polychlorinated biphenyl (PCB) congeners differentially reduce serum thyroxine (T4) in rats, but little is known about their ability to affect biliary excretion of T4. Thus, male Sprague-Dawley rats were orally administered Aroclor-1254, Aroclor-1242 (32 mg/kg per day), PCB-95, PCB-99, PCB-118 (16 mg/kg per day), PCB-126 (40 ?g/kg per day), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (3.9 ?g/kg per day), or corn oil for 7 days. Twenty-four hours after the last dose, [125I]T4 was administered intravenously, and blood, bile, and urine samples were collected for quantifying [125I]T4 and in bile [125I]T4 metabolites. Serum T4 concentrations were reduced by all treatments, but dramatic reductions occurred in response to Aroclor-1254, PCB-99 [phenobarbital (PB)-type congener], and PCB-118 (mixed-type congener). None of the treatments increased urinary excretion of [125I]T4. Aroclor-1254, PCB-118, TCDD, and PCB-126 (TCDD-type congener) increased biliary excretion of T4-glucuronide by 850, 756, 710, and 573%, respectively, corresponding to marked induction of hepatic UDP-glucuronosyltransferase (UGT) activity toward T4. PCB-95 and PCB-99 did not induce UGT activity; therefore, the increased biliary excretion of T4-glucuronide was related to the affinity of congeners for the aryl hydrocarbon receptor. The disappearance of [125I]T4 from serum was rapid (within 15-min) and was increased by Aroclor-1254, PCB-99 and PCB-118. Thus, reductions in serum T4 in response to PCBs did not always correspond with UGT activity toward T4 or with increased biliary excretion of T4-glucuronide. The rapid disappearance of [125I]T4 from the serum of rats treated with PB-like PCBs suggests that increased tissue uptake of T4 is an additional mechanism by which PCBs may reduce serum T4. PMID:22187485

Martin, L. A.; Wilson, D. T.; Reuhl, K. R.; Gallo, M. A.

2012-01-01

238

Effect of hair care and hair cosmetics on the concentrations of fatty acid ethyl esters in hair as markers of chronically elevated alcohol consumption  

Microsoft Academic Search

Fatty acid ethyl esters (FAEE) can be used as alcohol markers in hair. It was investigated in this study whether this diagnostic method is disturbed by hair care and hair cosmetics. Traces of ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate were detected in all of 49 frequently applied hair care products by headspace solid phase microextraction (HS-SPME) and

Sven Hartwig; Volker Auwärter; Fritz Pragst

2003-01-01

239

Higher urine 1-hydroxy pyrene glucuronide (1-OHPG) is associated with tobacco smoke exposure and drinking mat? in healthy subjects from Rio Grande do Sul, Brazil  

PubMed Central

Background The highest rates of esophageal squamous cell carcinoma (ESCC) in Brazil occur in Rio Grande do Sul, the most southern state, which has incidence rates of 20.4/100,000/year for men and 6.5/100,000/year for women. Exposure to carcinogenic polycyclic aromatic hydrocarbons (PAHs) through tobacco smoke and other sources may increase the risk of ESCC. The aims of the current study were to investigate the degree and sources of PAH exposure of the inhabitants of this region of southern Brazil. Methods Two hundred healthy adults (half smokers, half non smokers, half male and half female) were recruited, given a standardized questionnaire, and asked to provide a urine sample for measurement of 1-hydroxypyrene glucuronide (1-OHPG), a PAH metabolite). Urine 1-OHPG concentrations were measured using immunoaffinity chromatography and synchronous fluorescence spectroscopy and urine cotinine was measured using a dipstick test. We examined factors associated with 1-OHPG concentration using Wilcoxon tests and multiple linear regression. Results Urine 1-hydroxypyrene glucuronide (1-OHPG) was successfully measured on 199 subjects. The median (interquartile range) of urine 1-OHPG in the 199 participants was 2.09 pmol/mL (0.51, 5.84). Tobacco smoke exposure and maté drinking were statistically significantly associated with higher urine 1-OHPG concentrations in the multivariate linear regression model. Conclusion Tobacco smoke and maté both contribute to high levels of benzo[a]pyrene exposure in the people of southern Brazil. This high PAH exposure may contribute to the high rates of ESCC observed in this population. The increased urine 1-OHPG concentrations associated with maté suggest that contaminants, not just thermal injury, may help explain the increased risk of ESCC previously reported for maté consumption. PMID:16729889

Fagundes, Renato B; Abnet, Christian C; Strickland, Paul T; Kamangar, Farin; Roth, Mark J; Taylor, Philip R; Dawsey, Sanford M

2006-01-01

240

40 CFR 721.10130 - Quino[2,3-b]acridine-7,14-dione, 5,12-dihydro-ar-[4-[[2-(sulfooxy)ethyl]substituted]phenyl...  

Code of Federal Regulations, 2010 CFR

...2-(sulfooxy)ethyl]substituted]phenyl]-, monosodium salt (generic). ...2-(sulfooxy)ethyl]substituted]phenyl]-, monosodium salt (generic). ...2-(sulfooxy)ethyl]substituted]phenyl]-, monosodium salt (PMN...

2010-07-01

241

Domino inverse electron demand Diels-Alder reactions of chromones with ethyl vinyl ether .  

E-print Network

??E)-Ethyl 3-(4-oxo-4H-chromen-3-yi)acrylate (3), (E)-3-(4-oxo-4H-chromen-3-yl)-2-propenenitrile (12) and their 5-hydroxy-derivatives 11 and 13 undergo alternative, solvent dependent, domino reactions with ethyl vinyl ether. Inverse electron demand Diels-Alder… (more)

Heredia Moya, Jorge

2007-01-01

242

Iron pentacarbonyl-halogen-initiated reaction of ethyl acetoacetate and acetylacetone with acrylic monomers  

SciTech Connect

The authors have found that ethyl acetoacentate (EAA) and acetylacetone add to the double bond of acrylic monomers in the presence of the initiating system Fe(CO)/sub 5/ + Br/sub 2/(IS). The iron pentacarbonyl-bromine system initiates the addition reactions of ethyl acetoacetate and acetylacetone with the double bonds of acrylic monomers.

Amriev, R.A.; Abdulkina, Z.A.; Friedlina, R.K.; Velichko, F.K.

1985-05-20

243

The effect of benzoic acid or its ethyl ester on rumen fermentation parameters  

E-print Network

The effect of benzoic acid or its ethyl ester on rumen fermentation parameters J Nousiainen Valio be used as mould and yeast inhibitors in silage additives to improve the aerobic stability of silage response of BA or its ethyl ester (EB) on the rumen fermentation parameters in the continuous culture

Paris-Sud XI, Université de

244

Ethyl levulinate: A potential bio-based diluent for biodiesel which improves cold flow properties  

Microsoft Academic Search

Biodiesel, defined as mono-alkyl esters of long-chain fatty acids derived from vegetable oils or animal fats, is an attractive renewable fuel alternative to conventional petroleum diesel fuel. Biodiesel produced from oils such as cottonseed oil and poultry fats suffer from extremely poor cold flow properties because of their high saturated fatty acid content. In the current study, Ethyl Levulinate (ethyl

Hem Joshi; Bryan R. Moser; Joe Toler; William F. Smith; Terry Walker

2011-01-01

245

Combustion chemical kinetics of biodiesel and related compounds (methyl and ethyl esters): Experiments and  

E-print Network

1 Combustion chemical kinetics of biodiesel and related compounds (methyl and ethyl esters transportation fuel dedicated to the diesel engine, biodiesel, with an emphasis on ethyl esters because of biodiesel and related components, the main gaps in the field are highlighted to facilitate the convergence

Paris-Sud XI, Université de

246

The mid-IR spectra of 9-ethyl guanine, guanosine, and 2-deoxyguanosine  

E-print Network

The mid-IR spectra of 9-ethyl guanine, guanosine, and 2- deoxyguanosine Ali Abo-riziq(a) , Bridgit for Complex Molecular Systems and Biomolecules, 166 10 Prague 6, Czech Republic Abstract We present the mid-IR (400-1800 cm-1 ) spectra of 9-ethyl guanine, guanosine, and 2- deoxyguanosine measured by IR-UV double

de Vries, Mattanjah S.

247

(R)-1-Phenyl-ethyl-ammonium trifluoro-acetate.  

PubMed

In the crystal structure of the title salt, C(8)H(12)N(+)·C(2)F(3)O(2) (-), all of the ammonium H atoms serve as donors for hydrogen bonds to carboxyl-ate O atoms, forming an R(4) (3)(10) ring motif based on two cations and two anions. Since both cations and anions act as inter-ion bridging groups, R(10) rings aggregate in a one-dimensional supra-molecular network by sharing the strongest N-H?O bond. Edge-sharing motifs lie on the twofold screw axis parallel to [010], and anti-parallel packing of these 2(1)-column structural units results in the crystal structure. This arrangement is one of the most commonly occurring in conglomerates of chiral 1-phenyl-ethyl-amine with achiral monocarboxylic acids, confirming that these ionic salts are particularly robust supra-molecular heterosynthons useful in crystal engineering. PMID:21579169

Hernández Linares, María-Guadalupe; Guerrero Luna, Gabriel; Bernès, Sylvain

2010-01-01

248

Interaction of Ethyl Alcohol Vapor with Sulfuric Acid Solutions  

NASA Technical Reports Server (NTRS)

We investigated the uptake of ethyl alcohol (ethanol) vapor by sulfuric acid solutions over the range approx.40 to approx.80 wt % H2SO4 and temperatures of 193-273 K. Laboratory studies used a fast flow-tube reactor coupled to an electron-impact ionization mass spectrometer for detection of ethanol and reaction products. The uptake coefficients ((gamma)) were measured and found to vary from 0.019 to 0.072, depending upon the acid composition and temperature. At concentrations greater than approx.70 wt % and in dilute solutions colder than 220 K, the values approached approx.0.07. We also determined the effective solubility constant of ethanol in approx.40 wt % H2SO4 in the temperature range 203-223 K. The potential implications to the budget of ethanol in the global troposphere are briefly discussed.

Leu, Ming-Taun

2006-01-01

249

Fungal degradation of an acetolactate synthase (ALS) inhibitor pyrazosulfuron-ethyl in soil.  

PubMed

Owing to reported phytotoxicity of some sulfonylurea class of herbicides in number of sensitive crops and higher persistence in soil, present study was conducted to isolate and identify pyrazosulfuron-ethyl degrading fungi from soil of rice field. Penicillium chrysogenum and Aspergillus niger, were isolated and identified from rhizospere soil of rice field, as potent pyrazosulfuron-ethyl degrading fungi. Degradation of pyrazosulfuron-ethyl by P. chrysogenum and A. niger, yielded transformation products/metabolites which were identified and characterized by LC/MS/MS. The rate of dissipation of pyrazosulfuron-ethyl was found higher in soil of rice field and soil inoculated with P. chrysogenum. This showed important route of degradation of pyrazosulfuron-ethyl by microbes apart from chemical degradation. PMID:23993642

Sondhia, Shobha; Waseem, Uzma; Varma, R K

2013-11-01

250

COMPARATIVE GENOTOXICITY STUDIES OF ETHYL CARBAMATE AND RELATED CHEMICALS: FURTHER SUPPORT FOR VINYL CARBAMATE AS A PROXIMATE CARCINOGENIC METABOLITE  

EPA Science Inventory

In vivo and/or in vitro mammalian cell systems were used to evaluate sister chromatid exchange (SCE) induction and gene mutagenesis effects following exposure to ethyl carbamate (urethane), vinyl carbamate, ethyl N-hydroxycarbamate, and 2-hydroxyethyl carbamate....

251

Pd-Catalyzed O-Arylation of Ethyl Acetohydroximate: Synthesis of O-Arylhydroxylamines and Substituted Benzofurans  

E-print Network

An efficient Pd catalyst for the O-arylation of ethyl acetohydroximate with aryl chlorides, bromides, and iodides has been developed. Ethyl acetohydroximate serves as an efficient hydroxylamine equivalent for C?O cross-coupling, ...

Maimone, Thomas

252

Immunotoxicity of ethyl carbamate in female BALB/c mice: role of esterase and cytochrome P450.  

PubMed

Ethyl carbamate, a potent carcinogen, has been characterized to be metabolized by cytochrome P450 (P450) and esterase. It has recently been demonstrated that P450 may activate ethyl carbamate to immunotoxic metabolites. To investigate the role of esterase in ethyl carbamate-induced immunosuppression, mice were pretreated intraperitoneally with an esterase inhibitor, diazinon, at 20 mg/kg 30 min prior to the administration of ethyl carbamate intraperitoneally at 100 and 400 mg/kg for 7 consecutive days. Pretreatment with diazinon completely blocked the serum esterase activity. Histopathologically splenic and thymic atrophy was observed when mice were treated with ethyl carbamate, which was potentiated by the pretreatment with diazinon. In spleen, lymphocytes in the periarteriolar lymphoid sheath and the marginal zone appeared to be depleted in the white pulps. In thymus, ethyl carbamate caused a marked depletion of cells in cortex. The antibody response to sheep red blood cells (SRBCs) was more suppressed by ethyl carbamate in diazinon-pretreated groups than in corn oil-pretreated groups. These results suggest that the metabolism of ethyl carbamate by esterase may be an inactivation pathway in ethyl carbamate-induced immunosuppression. In addition, ethyl N-hydroxycarbamate, a P450 metabolite, suppressed the lymphoproliferative response induced by lipopolysaccharide and concanavalin A in splenocyte cultures. These results indicate that the metabolism of ethyl carbamate by P450 may be an activation pathway in immunosuppression by ethyl carbamate. PMID:10814887

Cha, S W; Gu, H K; Lee, K P; Lee, M H; Han, S S; Jeong, T C

2000-06-01

253

21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.  

...false Methyl and ethyl esters of fatty acids produced from edible fats and oils. ...225 Methyl and ethyl esters of fatty acids produced from edible fats and oils. Methyl esters and ethyl esters of fatty acids produced from edible fats and oils...

2014-04-01

254

21 CFR 176.160 - Chromium (Cr III) complex of N-ethyl-N-heptadecylfluoro-octane sulfonyl glycine.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2009-04-01 true Chromium (Cr III) complex of N-ethyl-N-heptadecylfluoro-octane...Paper and Paperboard § 176.160 Chromium (Cr III) complex of N -ethyl-N...heptadecylfluoro-octane sulfonyl glycine. The chromium (Cr III) complex of N- ethyl -...

2010-04-01

255

21 CFR 176.160 - Chromium (Cr III) complex of N-ethyl-N-heptadecylfluoro-octane sulfonyl glycine.  

...2014-04-01 2014-04-01 false Chromium (Cr III) complex of N-ethyl-N-heptadecylfluoro-octane...Paper and Paperboard § 176.160 Chromium (Cr III) complex of N -ethyl-N...heptadecylfluoro-octane sulfonyl glycine. The chromium (Cr III) complex of N- ethyl -...

2014-04-01

256

21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.  

Code of Federal Regulations, 2012 CFR

...ethyl esters of fatty acids produced from edible fats and oils. 172.225 Section...ethyl esters of fatty acids produced from edible fats and oils. Methyl esters and ethyl esters of fatty acids produced from edible fats and oils may be safely used in...

2012-04-01

257

21 CFR 172.225 - Methyl and ethyl esters of fatty acids produced from edible fats and oils.  

Code of Federal Regulations, 2013 CFR

...ethyl esters of fatty acids produced from edible fats and oils. 172.225 Section...ethyl esters of fatty acids produced from edible fats and oils. Methyl esters and ethyl esters of fatty acids produced from edible fats and oils may be safely used in...

2013-04-01

258

Mechanism of quizalofop-ethyl selectivity in monocotyledonous and dicotyledonous species  

SciTech Connect

Cucumber (Cucumis sativus L.) susceptibility to quizalofop-ethyl herbicide was investigated under field and greenhouse conditions. Yield of cucumber cultivars was significantly reduced under field conditions with a single or repeat application of the ethyl ester of quizalofop at 0.14 or 0.28 kg ai/ha. Under greenhouse conditions, quialofop-ethyl significantly suppressed cucumber plant fresh weight with or without the presence of an adjuvant. Enhancement of herbicide activity was directly related to concentration of adjuvant. Microliter droplet application of quizalofop-ethyl at a 10/sup -3/ M concentration, inhibited the relative growth (RGR) and net assimilation rate (NAR) of the treated cucumber leaf 45% and 52%, respectively. Expression of herbicidal injury was localized on the treated leaf with no visible symptoms observed on adjacent leaves. Radiolabeled /sup 14/C-quizalofop-ethyl was applied to leaves of cucumber and corn (Zea mays L.) to compare translocation patterns between two susceptible plant species and relate this information to the observed selectivity of the herbicide. Cucumber autoradiographs showed minimal translocation of /sup 14/C-quizalofop-ethyl 192 hours after treatment. In contrast, corn autoradiographs showed both apoplastic and symplastic transport of quizalofop-ethyl 3 and 24 hours after treatment. Quantification of /sup 14/C in cucumber revealed 96% of absorbed /sup 14/C was confined to the treated leaf after 192h of exposure.

Ruizzo, M.A.

1986-01-01

259

Reactions of Ethyl Groups on a Model Chromia Surface: Ethyl Chloride on Stoichiometric Alpha-Cr2O3(1012)  

SciTech Connect

The reaction of CH3CH2Cl over the nearly-stoichiometric ?-Cr2O3 (1 0 View the MathML source 2) surface yields gas phase CH2double bond; length as m-dashCH2, CH3CH3, H2 and surface chlorine adatoms. The decomposition reaction is initiated via C-Cl bond cleavage to give a surface ethyl (CH3CH2-) intermediate. A rate-limiting ?-hydride elimination from the surface ethyl species produces gas phase CH2double bond; length as m-dashCH2 and surface hydrogen atoms. Two parallel competing reactions form CH3CH3, via ?-hydride addition to remaining surface ethyl species (reductive elimination), and H2, via the combination of two surface hydrogen atoms. The chlorine freed from the dissociation of CH3CH2Cl binds at the five-coordinate surface Cr3+ sites on the stoichiometric surface and inhibits the surface chemistry via simple site blocking. No surface carbon deposition is observed from the thermal reaction of ethyl chloride, suggesting that ethyl intermediates are not primary coke forming intermediates in the dehydrogenation of ethane over (1 0 View the MathML source 2) facets of ?-Cr2O3.

Brooks, J.; Ma, Q; Cox, D

2009-01-01

260

Estimation of quizalofop ethyl residues in black gram (Vigna mungo L.) by gas liquid chromatography.  

PubMed

Quizalofop ethyl, a phenoxy propionate herbicide is used for post emergence control of annual and perennial grass weeds in broad-leaved crops in India. The experiments were designed to study the harvest time residues of quizalofop ethyl in black gram for two seasons. At harvest time, the residues of quizalofop ethyl on black gram seed, foliage and soil were found to be below the determination limit of 0.01 mg kg(-1) following a single application of the herbicide at 50 and 100 g a.i. ha(-1) for both the periods. Application of the herbicide is quite safe from a consumer and environmental point of view. PMID:24275886

Mandal, Kousik; Sahoo, Sanjay Kumar; Battu, R S; Singh, Balwinder

2014-01-01

261

Ethyl cellulose nanoparticles: clarithomycin encapsulation and eradication of H. pylori.  

PubMed

The extreme acidic environment of the stomach, its regular voidance of contents and the restricted access to the mucus covered habitat combined with the antibiotic resistance of the bacteria, all contribute to the poor success in the treatment of Helicobacter pylori gastric infections. Here, we demonstrate that by encapsulating clarithromycin into ethyl cellulose (EC) nanoparticles, the efficiency of H. pylori clearance in C57BL/6 mice infected with these bacteria was significantly improved. Clarithomycin-loaded EC nanoparticles were prepared via a simple yet effective anti-solvent particle induction method, to yield sub-micron sized particles with 22.3 ± 0.17% (w/w) clarithromycin loading at 86 ± 0.5% (w/w) encapsulation efficiency. The particles dispersed well in water and simulated gastric fluid and gave a minimum inhibitory concentration of 0.09-0.18 ?g/ml against four strains of H. pylori. Encapsulation into EC particles not only enhanced the anti-adhesion activity of clarithromycin when tested with H. pylori and Hep-2 cells, but also gave significant enhancement of H. pylori clearance in the stomach of C57BL/6 mice infected with the bacteria. PMID:24815396

Pan-In, Porntip; Banlunara, Wijit; Chaichanawongsaroj, Nuntaree; Wanichwecharungruang, Supason

2014-08-30

262

Ethyl cyanide on Titan: Spectroscopic detection and mapping using ALMA  

E-print Network

We report the first spectroscopic detection of ethyl cyanide (C$_2$H$_5$CN) in Titan's atmosphere, obtained using spectrally and spatially resolved observations of multiple emission lines with the Atacama Large Millimeter/submillimeter array (ALMA). The presence of C$_2$H$_5$CN in Titan's ionosphere was previously inferred from Cassini ion mass spectrometry measurements of C$_2$H$_5$CNH$^+$. Here we report the detection of 27 rotational lines from C$_2$H$_5$CN (in 19 separate emission features detected at $>3\\sigma$ confidence), in the frequency range 222-241 GHz. Simultaneous detections of multiple emission lines from HC$_3$N, CH$_3$CN and CH$_3$CCH were also obtained. In contrast to HC$_3$N, CH$_3$CN and CH$_3$CCH, which peak in Titan's northern (spring) hemisphere, the emission from C$_2$H$_5$CN is found to be concentrated in the southern (autumn) hemisphere, suggesting a distinctly different chemistry for this species, consistent with a relatively short chemical lifetime for C$_2$H$_5$CN. Radiative transf...

Cordiner, M A; Nixon, C A; Irwin, P G J; Teanby, N A; Charnley, S B; Mumma, M J; Kisiel, Z; Serigano, J; Kuan, Y -J; Chuang, Y -L; Wang, K -S

2014-01-01

263

Fatty acid ethyl esters. Ethanol metabolites that reflect ethanol intake.  

PubMed

Fatty acid ethyl esters (FAEEs) are nonoxidative ethanol metabolites that have been implicated as mediators of alcohol-induced organ damage. FAEEs are detectable in the blood after ethanol ingestion, and on that basis represent markers of ethanol intake. FAEEs have also been quantitated in human liver and adipose tissue and have been shown to be postmortem markers of premortem ethanol intake. A substantial difference in FAEE concentration was found in liver and adipose tissue of patients with detectable blood ethanol at the time of autopsy vs those with no detectable blood ethanol, who were either chronic alcoholics or social drinkers. Most currently available diagnostic markers for chronic alcoholism have limited clinical utility. Data in this report demonstrate that the amount or type of FAEEs can be used to differentiate a chronic alcoholic from an episodic heavy drinker (binage drinker) at or near peak blood ethanol concentrations and approximately 24 hours after discontinuation of ethanol. Thus, FAEEs are markers of ethanol intake in blood and tissues and can be useful in distinguishing chronic alcoholics from binge drinkers. PMID:12951847

Soderberg, Britt L; Salem, Raneem O; Best, Catherine A; Cluette-Brown, Joanne E; Laposata, Michael

2003-06-01

264

Theoretical Study of the Vibrational Spectroscopy of the Ethyl Radical  

NASA Astrophysics Data System (ADS)

The rich spectroscopy of the ethyl radical has attracted the attention of several experimental and theoretical investigations. The purpose of these studies was to elucidate the signatures of hyperconjugation, torsion, inversion, and Fermi coupling in the molecular spectra. Due to the number of degrees of freedom in the system, previous theoretical studies have implemented reduced-dimensional models. Our ultimate goal is a full-dimensional theoretical treatment of the vibrations using both Van Vleck and variational approaches. The methods will be combined with the potential that we have calculated using the CCSD(T) method on the cc-pVTZ basis set. In this talk we will discuss our initial work, which builds up from these reduced-dimensional models. Our calculations use coordinates that exploit the system's G_{12} PI symmetry in a simple fashion. By systematically adding more degrees of freedom to our model, we can determine the effects of specific couplings on the spectroscopy. T. Häber, A. C. Blair, D. J. Nesbitt and M. D. Schuder J. Chem. Phys. {124}, 054316, (2006). G .E. Douberly, unpublished. R. S. Bhatta, A. Gao and D. S. Perry J. Mol. Struct.: THEOCHEM {941}, 22, (2010).

Tabor, Daniel P.; Sibert, Edwin. L. Sibert, Iii

2013-06-01

265

Gauche Ethyl Alcohol: Laboratory Assignments and Interstellar Identification  

NASA Technical Reports Server (NTRS)

Ethyl alcohol (ethanol) is known to possess a pair of closely spaced excited torsional substates (gauche+, gauche-) at an energy of approximately 57 K above the ground (trans) torsional substate. We report an extended analysis of some gauche - gauche+ Q-branch ((Delta)J = 0) transitions with a three-substate fixed frame axis method (FFAM) Hamiltonian. Our approach accounts for complex trans-gauche interactions for the first time. In addition, we are able to obtain intensities for perturbed rotational transitions, and to determine the trans to gauche+ separation to be 1185399.1 MHz. A complete ground state rotational-torsional partition function accounting for the previously neglected gauche substates is presented. Based on our analysis, a total of 14 U lines obtained towards Orion KL can now be assigned to gauche substates of ethanol. Analysis of these lines yields a rotational temperature of 223 K and a total (trans + gauche) column density of 7.0 x 10(exp 15)/sq cm. The column density is in reasonable agreement with the recent value of 2-3 x 10(exp 15)/sq cm based on observations of trans-ethanol by Ohishi et al., although there is some disparity in the rotational temperatures. Eight additional U lines in the literature are assigned to transitions of gauche ethanol.

Pearson, J. C.; Sastry, K. V. L. N.; Herbst, Eric; DeLucia, Frank C.

1997-01-01

266

Orientational dynamics of the ionic organic liquid 1-ethyl-3-methylimidazolium nitrate  

E-print Network

Orientational dynamics of the ionic organic liquid 1-ethyl-3-methylimidazolium nitrate Hu Cang, Jie-methylimidazolium nitrate (EMIM NO3 ) over time scales from 1 ps to 2 ns, and the temperatures range from 410 to 295

Fayer, Michael D.

267

Hydrogen-Abstraction Reactions by Ethyl Radicals from Methylamines and Hydrazine.  

National Technical Information Service (NTIS)

By photolysis of diethyl ketone in the presence of the amine or hydrazine Arrhenius parameters were obtained for hydrogen-abstraction reactions of the ethyl radicals with methylamine, dimethylamine, trimethylamine, and hydrazine. The activation energy for...

D. A. Edwards, J. A. Kerr, A. C. Lloyd, A. F. Trotman-Dickenson

1966-01-01

268

40 CFR 180.212 - S-Ethyl cyclohexylethylthio-carbamate; tolerances for residues.  

Code of Federal Regulations, 2012 CFR

...cyclohexylethylthio-carbamate; tolerances for residues. (a) General. Tolerances are established for residues of the herbicide S -ethyl cyclohexylethylthiocarbamate in or on the following food commodities: Commodity Parts per million...

2012-07-01

269

40 CFR 180.212 - S-Ethyl cyclohexylethylthio-carbamate; tolerances for residues.  

Code of Federal Regulations, 2010 CFR

...cyclohexylethylthio-carbamate; tolerances for residues. (a) General. Tolerances are established for residues of the herbicide S -ethyl cyclohexylethylthiocarbamate in or on the following food commodities: Commodity Parts per million...

2010-07-01

270

Base-switched annuloselectivity in the reactions of ethyl malonyl chloride and imines.  

PubMed

The base-switched annuloselectivity, namely [2 + 2] and [2 + 2 + 2] selectivity, in the reactions of ethyl malonyl chloride and imines is successfully realized. In the presence of the weak nucleophilic base 2-chloropyridine, the reactions deliver ethyl trans-?-lactam-3-carboxylates as the exclusive [2 + 2] products in up to 93% yields, while with the strong nucleophilic N-methylimidazole as the base, the reactions give rise to 2,3-dihydro-1,3-oxazin-4-one derivatives as the sole products in up to 99% yields via the formal [2 + 2 + 2] cycloaddition involving one molecule of the imine and two molecules of the ketene generated from malonyl chloride. Notably, ethyl trans-?-lactam-3-carboxylates are synthesized for the first time directly from the reactions of ethyl malonyl chloride and imines. Mechanistic discussions reveal that the annuloselectivity is controlled by the nucleophilicity of organic bases. PMID:25355462

Yang, Zhanhui; Li, Siqi; Zhang, Zhong; Xu, Jiaxi

2014-11-19

271

Conformal sulfated zirconia monolayer catalysts for the one-pot synthesis of ethyl levulinate from glucose.  

PubMed

Here we describe a simple route to creating conformal sulphated zirconia monolayers throughout an SBA-15 architecture that confers efficient acid-catalysed one-pot conversion of glucose to ethyl levulinate. PMID:25144908

Morales, Gabriel; Osatiashtiani, Amin; Hernández, Blanca; Iglesias, Jose; Melero, Juan A; Paniagua, Marta; Brown, D Robert; Granollers, Marta; Lee, Adam F; Wilson, Karen

2014-10-11

272

Optimizing dosage of sethoxydim and fenoxaprop- p-ethyl with adjuvants to control wild oat  

Microsoft Academic Search

Using adjuvants to optimize and increase the efficacy of herbicides is an acceptable manner to reduce herbicides undesirable impact on the environment. Therefore, to detect suitable adjuvants for sethoxydim or fenoxaprop-p-ethyl, two dose–response experiments were conducted separately. The treatments consisted of six doses of sethoxydim or fenoxaprop-p-ethyl with and without adjuvants of Frigate, Citogate and Adigor against wild oat (Avena

Mohammad Hassan Rashed Mohassel; Akbar Aliverdi; Salman Rahimi

2011-01-01

273

New Technical Synthesis of Ethyl ( R)-2Hydroxy4-phenylbutyrate of High Enantiomeric Purity  

Microsoft Academic Search

A new technical synthesis to produce ethyl (R)-2-hydroxy-4-phenylbutyrate (5), an important intermediate for several ACE inhibitors with >99% ee in an over-all yield of 50–60% is described starting from acetophenone and diethyl oxalate. Key step is the chemo- and enantioselective hydrogenation of ethyl 2,4-dioxo-4-phenylbutyrate (6) (ee up to 86%) catalyzed by a heterogeneous Pt catalyst modified with dihydrocinchonidine, followed by

P Herold; A. F Indolese; M Studer; H. P Jalett; U Siegrist; H. U Blaser

2000-01-01

274

Synthesis and Characterization of a Gasoline Oxygenate, Ethyl tertButyl Ether  

Microsoft Academic Search

A laboratory procedure involving the synthesis and characterization of ethyl tert-butyl ether (ETBE) is described. This experiment has been used in a general chemistry sequence that includes a section on organic chemistry, but is also well suited for an introductory organic chemistry laboratory course. ETBE is prepared by the acid-catalyzed reaction of tert-butyl alcohol with ethyl alcohol. The product is

Craig J. Donahue; Teresa D'Amico; Jennifer A. Exline

2002-01-01

275

Ethyl chloride improves antiseptic effect of betadine skin preparation for office procedures.  

PubMed

To determine if ethyl chloride is an effective disinfectant alone or combined with povidone iodine in a clinical setting, 35 volunteers had different portions of their knees swabbed with sterile cotton-tip applicators after an area of skin was prepared with either ethyl chloride alone, povidone iodine alone, or povidone iodine followed by ethyl chloride. An area with no preparation at all served as the control. Specimens were then cultured on agar plates and bacterial growth assessed. When the data was categorized as colony forming units (CFUs) or no CFUs, both ethyl chloride and povidone iodine used alone had significantly fewer specimens with CFUs (p=0.001) than controls, but were not significantly different from each other (p=0.18). Additionally, the combination of povidone iodine followed by ethyl chloride spray had significantly fewer samples with CFUs than either product used alone (p=0.001). In addition to its local anesthetic properties, ethyl chloride may be an effective disinfectant alone and may improve skin disinfection when used with povidone iodine compared to povidone iodine alone. PMID:22995356

Azar, Frederick M; Lake, Jason E; Grace, Sean P; Perkinson, Brian

2012-01-01

276

Lignin biodegradation and the production of ethyl alcohol from cellulose  

SciTech Connect

During the last few years our group has been engaged in developing a biochemical process for the conversion of lignocellulosic materials to ethyl alcohol. Lignin is a barrier to complete cellulose saccharification in this process, but chemical and physical delignification steps are too expensive to be used at the present time. An enzymatic delignification process might be attractive for several reasons: little energy would be expected to be needed, enzymes could be recovered and reused, and useful chemicals might be produced from dissolved lignin. A number of thermophilic and thermotolerant fungi were examined for the ability to rapidly degrade lignocellulose in order to find an organism whcih produced an active lignin-degrading enzyme system. Chryosporium pruinosum and Sporotrichum pulverulentum were found to be active lignocellulose degraders, and C. pruinosum was chosen for further study. Lignin and carbohydrate were degraded when the substrate remained moistened by, but not submerged in, the liquid medium. Attempts were made to demonstrate a cell-free lignin degrading system by both extraction and pressing of cultures grown on moist lignocellulose. Carbohydrate-degrading activity was found but not lignin-degrading activity. This led us to ask whether diffusible lignin-degrading activity could be demonstrated in this organism. The data indicate that the lignin degradation system, or one or more of its components, produced by this organism is either unstable, non-diffusible, or inactive at small distances (about 1 mm) from growing hyphae. At present, studies are being conducted using diffusion cultures to select mutants of C. pruinosum that do produce a diffusible lignin degradation system. We are also examining a number of mesophilic lignin-degrading molds for this ability.

Rosenberg, S.L.; Wilke, C.R.

1981-02-01

277

Ethylation of poly(dC-dG).poly(dC-dG) by ethyl methanesulfonate stimulates the activity of mammalian DNA methyltransferase in vitro.  

PubMed Central

Ethylation of poly(dC-dG).poly(dC-dG) with ethyl methanesulfonate (EtMes), a known carcinogen, at increasing molar ratios of EtMes/C X G base pairs progressively stimulated the methyl-accepting ability of the DNA during in vitro methylation by partially purified rat DNA (cytosine-5)-methyltransferase (EC 2.1.1.37). Maximum stimulation was 2-fold over mock-treated DNA when 2.7% of the guanines were modified at the N-7 position, the major site of ethylation by EtMes in DNA. If a CpG site "hemiethylated" at guanine N-7 mimics a hemimethylated CpG site, we calculate that the enzyme has a relative affinity for hemiethylated CpG 18-fold above unmodified CpG. If ethylation of a dioxyphosphate oxygen of the phosphodiester bond is responsible for stimulation, the relative affinity could be much higher, up to 370-fold. Images PMID:3856245

Farrance, I K; Ivarie, R

1985-01-01

278

Combination treatment with ethyl pyruvate and aspirin enhances neuroprotection in the postischemic brain.  

PubMed

Ethyl pyruvate (EP), a simple aliphatic ester of pyruvic acid, has been shown to act as an anti-inflammatory molecule in various pathological conditions, which include sepsis or hemorrhagic shock. Recently, we showed that ethyl pyruvate has a neuroprotective effect in the postischemic brain and also in KA-induced pathogenesis in the brain. In this study, we examined whether aspirin augments neuroprotective effect of ethyl pyruvate in transient focal ischemia model by complementing the neuroprotective effects of ethyl pyruvate. Although, most of neuroprotective effect of aspirin has been attributed to the anti-platelet action, aspirin also has direct neuroprotective effects, including NF-kappaB inhibition. Ethyl pyruvate dose-dependently suppressed infarct formation in the postischemic brain, wherein intravenous administration of 5 mg/kg ethyl pyruvate 30 min after the occlusion reduced infarct volume to 34.5 +/- 15.5% (n = 6, P < 0.01) of that of the untreated control. In combination with aspirin (5 mg/kg, i.v.), the neuroprotective effect was enhanced, resulting in 16.0 +/- 5.9% (n = 6, P < 0.01) infarct volume. The time window for synergistic neuroprotection by ethyl pyruvate and aspirin extended to 9 h post-MCAO. The synergistic reduction in infarct volume was accompanied by suppression of the clinical manifestations associated with cerebral ischemia including motor impairment and neurological deficits. Inflammatory processes including microglial activation and proinflammatory cytokine expression were notably suppressed by the combination treatment in the postischemic brain and in primary microglia cultures, wherein ethyl pyruvate and aspirin modulate NF-kappaB signaling differentially. Aspirin interferes with IkappaB phosphorylation and degradation in the cytoplasm, possibly by specifically inhibiting IkappaB kinase-beta, whereas, the effect of ethyl pyruvate seems to occur in the nucleus, where it may interfere with the binding of NF-kappaB to responsive promoter elements in the target genes. Similar enhancement in neuroprotective effect was also observed in primary cortical cultures after NMDA or Zn(2+) treatment or oxygen-glucose deprivation. Together, these results indicate that combination treatment of ethyl pyruvate and aspirin affords synergistic neuroprotection in the postischemic brain with a wide therapeutic window, in part via differential modulation of the NF-kappaB signaling pathway. PMID:19636661

Kim, Seung-Woo; Jeong, Ji-Young; Kim, Hyun Ji; Seo, Ji-Seon; Han, Pyung-Lim; Yoon, Sung-Hwa; Lee, Ja-Kyeong

2010-01-01

279

Mixture Toxicity of SN2-Reactive Soft Electrophiles: 2--Evaluation of Mixtures Containing Ethyl ?-Halogenated Acetates  

PubMed Central

Four ethyl ?-halogenated acetates were tested in (1) sham and (2) nonsham combinations and (3) with a nonreactive nonpolar narcotic. Ethyl iodoacetate (EIAC), ethyl bromoacetate (EBAC), ethyl chloroacetate (ECAC), and ethyl fluoroacetate (EFAC), each considered to be an SN2-H-polar soft electrophile, were selected for testing based on their differences in electro(nucleo)philic reactivity and time-dependent toxicity (TDT). Agent reactivity was assessed using the model nucleophile glutathione, with EIAC and EBAC showing rapid reactivity, ECAC being less reactive, and EFAC lacking reactivity at ?250 mM. The model nonpolar narcotic, 3-methyl-2-butanone (3M2B), was not reactive. Toxicity of the agents alone and in mixture was assessed using the Microtox acute toxicity test at three exposure durations: 15, 30 and 45 min. Two of the agents alone (EIAC and EBAC) had TDT values >100%. In contrast, ECAC (74 to 99%) and EFAC (9 to 12%) had partial TDT, whereas 3M2B completely lacked TDT (<0%). In mixture testing, sham combinations of each agent showed a combined effect consistent with predicted effects for dose-addition at each time point, as judged by EC50 dose-addition quotient values. Mixture toxicity results for nonsham ethyl acetate combinations were variable, with some mixtures being inconsistent with the predicted effects for dose-addition and/or independence. The ethyl acetate–3M2B combinations were somewhat more toxic than predicted for dose-addition, a finding differing from that observed previously for ?-halogenated acetonitriles with 3M2B. PMID:21452006

Mooneyham, T.; Jeyaratnam, J.; Schultz, T. W.; Poch, G.

2011-01-01

280

Biodegradation of pyrazosulfuron-ethyl by three strains of bacteria isolated from contaminated soils.  

PubMed

Three bacterial strains capable of transforming pyrazosulfuron-ethyl, designated as D61, D66, and D713, were isolated from pyrazosulfuron-ethyl contaminated soils. According to the sequence analysis of the partial 16S rRNA gene, it is found that the strains D61 and D66 belong to Pseudomonas sp., and the strain D713 belongs to Bacillus sp. The effects of pyrazosulfuron-ethyl concentration, pH and temperature on biodegradation were examined. At a concentration of 10.0mgL(-1), pyrazosulfuron-ethyl was completely degraded by Pseudomonas sp. D61 after 2d and by Pseudomonas sp. D66 after 5d. At a concentration of 90.0mgL(-1), pyrazosulfuron-ethyl can be completely degraded by Pseudomonas sp. D66 and D61 after 12d. More than 85.9% degradation rate was observed with Bacillus sp. D713 after 12d. The growth of these three strains was inhibited at low pH buffers. The abiotic degradation occurs much faster at low pH than at neutral and basic pH conditions. The degradation rate of pyrazosulfuron-ethyl at 28 degrees C was faster than those at 20 degrees C and 37 degrees C by these strains, except the highest degradation rate of Bacillus sp. D713 was obtained at 37 degrees C. The pyrazosulfuron-ethyl biodegradation products were identified by liquid chromatography-mass spectroscopy with positive/negative modes and tandem MS-MS techniques. The main degradation product was detected and identified as 5-(N-(4,6-dimethoxypyrimidin-2-ylcarbamoyl)sulfamoyl)-1-methyl-1H-pyrazole-4-carboxylic acid based on mass spectral data and fragmentation patterns. PMID:19004468

Xu, Jun; Li, Xuesheng; Xu, Yanjun; Qiu, Lihong; Pan, Canping

2009-02-01

281

Ethyl Pyruvate Ameliorates Hepatic Ischemia-Reperfusion Injury by Inhibiting Intrinsic Pathway of Apoptosis and Autophagy  

PubMed Central

Background. Hepatic ischemia-reperfusion (I/R) injury is a pivotal clinical problem occurring in many clinical conditions such as transplantation, trauma, and hepatic failure after hemorrhagic shock. Apoptosis and autophagy have been shown to contribute to cell death in hepatic I/R injury. Ethyl pyruvate, a stable and simple lipophilic ester, has been shown to have anti-inflammatory properties. In this study, the purpose is to explore both the effect of ethyl pyruvate on hepatic I/R injury and regulation of intrinsic pathway of apoptosis and autophagy. Methods. Three doses of ethyl pyruvate (20?mg/kg, 40?mg/kg, and 80?mg/kg) were administered 1?h before a model of segmental (70%) hepatic warm ischemia was established in Balb/c mice. All serum and liver tissues were obtained at three different time points (4?h, 8?h, and 16?h). Results. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), and pathological features were significantly ameliorated by ethyl pyruvate (80?mg/kg). The expression of Bcl-2, Bax, Beclin-1, and LC3, which play an important role in the regulation of intrinsic pathway of apoptosis and autophagy, was also obviously decreased by ethyl pyruvate (80?mg/kg). Furthermore, ethyl pyruvate inhibited the HMGB1/TLR4/ NF-?b axis and the release of cytokines (TNF-? and IL-6). Conclusion. Our results showed that ethyl pyruvate might attenuate to hepatic I/R injury by inhibiting intrinsic pathway of apoptosis and autophagy, mediated partly through downregulation of HMGB1/TLR4/ NF-?b axis and the competitive interaction with Beclin-1 of HMGB1. PMID:24453420

Shen, Miao; Lu, Jie; Dai, Weiqi; Wang, Fan; Xu, Ling; Chen, Kan; He, Lei; Cheng, Ping; Zhang, Yan; Wang, Chengfen; Wu, Dong; Yang, Jing; Zhu, Rong; Zhang, Huawei; Zhou, Yinqun; Guo, Chuanyong

2013-01-01

282

Antihyperglycemic effect of Hypericum perforatum ethyl acetate extract on streptozotocin-induced diabetic rats  

PubMed Central

Objective To evaluate the antihyperglycemic activity of ethyl acetate extract of Hypericum perforatum (H. perforatum) in streptozotocin (STZ)-induced diabetic rats. Methods Acute toxicity and oral glucose tolerance test were performed in normal rats. Male albino rats were rendered diabetic by STZ (40 mg/kg, intraperitoneally). H. perforatum ethyl acetate extract was orally administered to diabetic rats at 50, 100 and 200 mg/kg doses for 15 days to determine the antihyperglycemic activity. Biochemical parameters were determined at the end of the treatment. Results H. perforatum ethyl acetate extract showed dose dependant fall in fasting blood glucose (FBG). After 30 min of extract administration, FBG was reduced significantly when compared with normal rats. H. perforatum ethyl acetate extract produced significant reduction in plasma glucose level, serum total cholesterol, triglycerides, glucose-6-phosphatase levels. Tissue glycogen content, HDL-cholesterol, glucose-6-phosphate dehydrogenase were significantly increased compared with diabetic control. No death or lethal effect was observed in the toxic study. Conclusions The results demonstrate that H. perforatum ethyl acetate extract possesses potent antihyperglycemic activity in STZ induced diabetic rats. PMID:23569798

Arokiyaraj, S; Balamurugan, R; Augustian, P

2011-01-01

283

Metabolism of ( sup 14 C)quizalofop-ethyl in soybean and cotton plants  

SciTech Connect

The metabolism of (phenyl-U-{sup 14}C)quizalofop-ethyl or (quinoxaline-{sup 14}C)quizalofop-ethyl was investigated in soybean and cotton plants. ({sup 14}C)Quizalofop-ethyl was applied to soybean or cotton plants at 4 oz of AI/acre as a postemergence spray, and plant samples were harvested initially (day 0) and at 3, 6, and 13.5 (maturity) weeks after treatment. No detectable {sup 14}C residues (< 0.01 ppm) were found in mature beans or pods, whereas the mature fiber and seeds from the cotton contained 0.08 and 0.09 ppm total {sup 14}C residues, respectively. The proposed metabolic pathway of quizalofop-ethyl was similar in both soybean and cotton plants. In the foliage, quizalofop-ethyl was rapidly metabolized to 2-4-(6-chloroquinoxalin-2-yl)oxy-phenoxypropanoic acid (quizalofop) that metabolized to the phenol metabolites 6-chloroquinoxaline-2-ol and 2-(4-hydroxyphenoxy)propanoic acid. Glucose conjugates of quizalofop possibly were formed since addition of {beta}-glucosidase to aqueous extracts (containing polar {sup 14}C residues) of soybean foliage slowly released ({sup 14}C)quizalofop.

Koeppe, M.K.; Anderson, J.J.; Shalaby, L.M. (E.I. du Pont de Nemours and Co., Inc., Wilmington, DE (USA))

1990-04-01

284

Degradation behaviour of pyrazosulfuron-ethyl in water as affected by pH.  

PubMed

Pyrazosulfuron-ethyl, a new herbicide belonging to the sulfonylurea group, is used for weed control in rice crops growing in areas varying from acidic to alkaline soils. This study was undertaken to determine the degradation behaviour of pyrazosulfuron-ethyl in distilled water and buffer solutions at pH 4, 7 and 9. Degradation was pH-dependent and herbicide was least persistent in acidic pH followed by alkaline and neutral pH. The half-life of pyrazosulfuron-ethyl varied from 2.6 days (pH 4) to 19.4 days (pH 7) and half-life in distilled water was comparable to half-life at pH 7 buffer. HPLC analysis of different pH samples showed the formation of three metabolites viz., 5-(aminosulfonyl)-1-methyl-1H-pyrazole-4-carboxylic acid; ethyl 5-(aminosulfonyl)-1-methyl-1H-pyrazole-4-carboxylate and 2-amino-4,6-dimethoxy pyrimidine. The formation of pyrazosulfuron acid [5-([([(4,6-dimethoxy-2 pyrimidinyl)-amino]-carbonyl) amino]-sulfonyl)-1-methyl-1H-pyrazole-4-carboxylic acid] was not observed at any pH. The study indicated that the herbicide was least stable under acidic conditions and the predominant degradation route of pyrazosulfuron-ethyl in water is hydrolysis of sulfonamide linkage. PMID:23374044

Singh, Shashi B; Singh, Neera

2013-01-01

285

[Effects of allelochemicals ethyl cinnamate on the growth and physiological characteristics of Chlorella pyrenoidosa].  

PubMed

The effects of ethyl cinnamate on the growth and physiological characteristics of Chlorella pyrenoidosa were studied. The allelopathic mechanisms were explored, from views of chlorophyll a content, antioxidant enzyme activities, reactive oxygen species (ROS) level, malondialdehyde (MDA) content and photosynthetic activity. The results revealed that ethyl cinnamate had acute inhibitory effects on the growth of Chlorella pyrenoidosa, and the inhibited degree tended to increase with increased concentrations. The effective concentration causing a 50% inhibition at 96 h was 5.45 mg c L(-1). Ethyl cinnamate induced the decrease of chlorophyll a, the over-accumulation of ROS and the increase of MDA. Therefore, it suggested that ethyl cinnamate could lead to the damage of cell membrane system and metabolic disorder through inducing lipid peroxidation via initiating ROS overproduction. And for scavenging ROS, the algae cells were protected from oxidative damages through increasing the activity of antioxidant enzymes. The results demonstrated ethyl cinnamate had acute inhibition to the maximum quantum yield and the potential activity of photosystem II of Chlorella pyrenoidosa, however, the photosynthetic activity could recover to some extent through self-regulation after some time. PMID:23487932

Gao, Li-Li; Guo, Pei-Yong; Su, Guang-Ming; Wei, Yan-Fang

2013-01-01

286

Ethyl Radical Ejection During Photodecomposition of Butanone on TiO2(110)  

SciTech Connect

The photodecomposition of acetone and butanone were examined on the (110) surface of rutile TiO2 using temperature programmed desorption (TPD) and photon stimulated desorption (PSD). In both cases, photodecomposition was proceeded by a required thermal reaction between the adsorbed ketone and coadsorbed oxygen resulting in a diolate species. The diolate photodecomposed by ejection of an organic radical from the surface leaving behind a carboxylate species. In the acetone case, only methyl radical PSD was detected and acetate was left on the surface. In the butanone case there was a possibility of either methyl or ethyl radical ejection, with propionate or acetate left behind, respectively. However, only ethyl radical PSD was detected and the species left on the surface (acetate) was the same as in the acetone case. The preference for ethyl radical ejection is linked to the greater thermal stability of the ethyl radical over that of the methyl radical. Unlike in the acetone case, where the ejected methyl radicals did not participate in thermal chemistry on the TiO2(110) surface after photoactivation of the acetone diolate, ethyl radicals photodesorbing at 100 K from butanone diolate showed a preference for dehydrogenation to ethene through the influence of coadsorbed oxygen. These results reemphasize the mechanistic importance of organic radical production during photooxidation reactions on TiO2 surface.

Henderson, Michael A.

2008-10-15

287

Ethyl Radical Ejection During Photodecomposition of Butanone on TiO2(110)  

SciTech Connect

The photodecomposition of acetone and butanone were examined on the (110) surface of rutile TiO2 using temperature programmed desorption (TPD) and photon stimulated desorption (PSD). In both cases, photodecomposition was proceeded by a required thermal reaction between the adsorbed ketone and coadsorbed oxygen resulting in a diolate species. The diolate photodecomposed by ejection of an organic radical from the surface leaving behind a carboxylate species. In the acetone case, only methyl radical PSD was detected and acetate was left on the surface. In the butanone case there was a possibility of either methyl or ethyl radical ejection, with propionate or acetate left behind, respectively. However, only ethyl radical PSD was detected and the species left on the surface (acetate) was the same as in the acetone case. The preference for ethyl radical ejection is linked to the greater thermal stability of the ethyl radical over that of the methyl radical. Unlike in the acetone case, where the ejected methyl radicals did not participate in thermal chemistry on the TiO2(110) surface after photoactivation of the acetone diolate, ethyl radicals photodesorbing at 100 K from butanone diolate showed a preference for dehydrogenation to ethene through the influence of coadsorbed oxygen. These results reemphasize the mechanistic importance of organic radical production during photooxidation reactions on TiO2 surface. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

Henderson, Michael A.

2008-10-15

288

Effect of Potent Ethyl Acetate Fraction of Stereospermum suaveolens Extract in Streptozotocin-Induced Diabetic Rats  

PubMed Central

To evaluate the antihyperglycemic effect of ethyl acetate fraction of ethanol extract of Stereospermum suaveolens in streptozotocin-(STZ-) induced diabetic rats by acute and subacute models. In this paper, various fractions of ethanol extract of Stereospermum suaveolens were prepared and their effects on blood glucose levels in STZ-induced diabetic rats were studied after a single oral administration (200?mg/kg). Administration of the ethyl acetate fraction at 200?mg/kg once daily for 14 days to STZ-induced diabetic rats was also carried out. The parameters such as the fasting blood glucose, hepatic glycogen content, and pancreatic antioxidant levels were monitored. In the acute study, the ethyl acetate fraction is the most potent in reducing the fasting serum glucose levels of the STZ-induced diabetic rats. The 14-day repeated oral administration of the ethyl acetate fraction significantly reduced the fasting blood glucose and pancreatic TBARS level and significantly increased the liver glycogen, pancreatic superoxide dismutase, and catalase activities as well as reduced glutathione levels. The histopathological studies during the subacute treatment have been shown to ameliorate the STZ-induced histological damage of pancreas. This paper concludes that the ethyl acetate fraction from ethanol extract of Stereospermum suaveolens possesses potent antihyperglycemic and antioxidant properties, thereby substantiating the use of plant in the indigenous system of medicine. PMID:22593683

Balasubramanian, T.; Chatterjee, Tapan Kumar; Senthilkumar, G. P.; Mani, Tamizh

2012-01-01

289

Identification, Ki determination and CoMFA analysis of nuclear receptor ligands as competitive inhibitors of OATP1B1-mediated estradiol-17?-glucuronide transport  

PubMed Central

Evidence shows that drug-drug interactions can occur at the level of drug transporters such as the organic anion transporting polypeptides (OATPs), a group of membrane solute carriers that mediate the sodium-independent transport of a wide range of amphipathic organic compounds. The polyspecific OATP1B1 is exclusively expressed at the basolateral membrane of hepatocytes and mediates uptake of amphipathic organic compounds from blood into hepatocytes. Nuclear receptors are ligand-activated transcription factors that play an important role in xenobiotic disposition and human diseases. Quite a few nuclear receptor ligands interact with transport proteins. A high-resolution three-dimensional structure is critical to understand the polyspecificity of OATP1B1 to predict and prevent adverse drug-drug interactions. Unfortunately there are no crystal structures of OATPs/Oatps available to date. Therefore, in this study we attempted to elucidate the characteristics of the substrate binding site of OATP1B1 based on small molecules interacting with it. First, we identified inhibitors of the OATP1B1 model substrate estradiol-17?-glucuronide from about forty nuclear receptor ligands. Among them, GW1929, paclitaxel and troglitazone were strong inhibitors, while 5?-androstane, 5?-androstane-3?, 17?-diol-17-hexahydrobenzoate and estradiol-3-benzoate were weak inhibitors. Then, we selected 25 compounds and performed inhibition kinetic studies to identify competitive inhibitors and determine their Ki values which ranged from submicromolar to submillimolar. Finally, we performed CoMFA analysis on the identified competitive inhibitors. The CoMFA results indicate that the substrate binding site of OATP1B1 consists of a large hydrophobic middle part with basic residues at both ends that could be very important for substrate binding. PMID:19427586

Gui, Chunshan; Wahlgren, Brett; Lushington, Gerald H.; Hagenbuch, Bruno

2009-01-01

290

Determination of ?- and ?-boldenone sulfate, glucuronide and free forms, and androstadienedione in bovine urine using immunoaffinity columns clean-up and liquid chromatography tandem mass spectrometry analysis.  

PubMed

The debate about the origins of boldenone in bovine urine is ongoing for two decades in Europe. Despite the fact that its use as a growth promoter has been banned in the European Union (EU) since 1981, its detection in bovine urine, in the form of ?-boldenone conjugate, is considered fully compliant up to 2ngmL(-1). The conjugated form of ?-boldenone must be absent. In recent years, the literature about boldenone has focused on the identification of biomarkers that can indicate an illicit treatment. ?-boldenone sulfate is a candidate molecule, even if the only studies currently available have taken place in small populations. In this study, a method for the determination of sulfate and glucuronate conjugates of ?-boldenone was developed and validated according to the European Commission Decision 2002/657/EC and applied to ?-boldenone sulfate and glucuronide, ?- and ?-boldenone free forms and androstadienedione (ADD), too. The clean-up with immunoaffinity columns enabled the direct determination of the conjugates and free forms and allowed specific and sensitive analyses of urine samples randomly selected to verify this method. The decision limits (CC?) ranged between 0.07 and 0.08ngmL(-1), the detection capabilities (CC?) between 0.08 and 0.1ngmL(-1). Recovery was higher than 92% for all the analytes. Intra-day repeatability was between 5.8% and 17.2%, and inter-day repeatability was between 6.0% and 21.8% for the studied free and conjugated forms. This method has been developed as a powerful tool with the aim to study the origin of boldenone in a trial on a significant number of animals. PMID:25281088

Chiesa, Luca; Pavlovic, Radmila; Dusi, Guglielmo; Pasquale, Elisa; Casati, Alessio; Panseri, Sara; Arioli, Francesco

2015-01-01

291

Biotransformation of an alpha4beta2 nicotinic acetylcholine receptor partial agonist in sprague-dawley rats and the dispositional characterization of its N-carbamoyl glucuronide metabolite.  

PubMed

The metabolism and disposition of (1S,5R)-2,3,4,5-tetrahydro-7-(trifluoromethyl)-1,5-methano-1H-3-benzazepine (1), an alpha(4)beta(2) nicotinic acetylcholine receptor partial agonist, was determined in Sprague-Dawley rats after oral administration of [(14)C]1. In intact animals, mass balance was achieved within 48 h, with 5 times more radioactivity excreted in urine than in feces. Compound 1 underwent renal and metabolic clearance equally and exhibited a very long half-life attributable to a secondary peak occurring 8 h postdose in its serum concentration-time curve. In bile duct-cannulated (BDC) rats, mass balance was also achieved within 48 h with 73.7, 23.4, and 5.5% of the dose detected in bile, urine, and feces, respectively. Rats metabolized 1 by two primary routes: four-electron oxidation to either four amino acids or a lactam and formation of an N-carbamoyl glucuronide (M6), which was only detected in bile. The presence of M6 solely in bile and the double-humped serum concentration-time curve of 1 suggested the indirect enterohepatic cycling of 1 via M6 after oral administration. To explore this mechanistic hypothesis further, intravenous studies were conducted with 1 in both intact and BDC rats to determine the extent of 1 undergoing indirect enterohepatic cycling via M6. Compared with the pharmacokinetics in intact rats, total serum clearance was higher (1.7-fold) and volume of distribution was lower (1.6-fold) in BDC rats, resulting in a correspondingly shorter (2.5-fold) half-life, with 56% of administered 1 undergoing recirculation, an amount consistent with that (68% of dose) of M6 observed in bile from rats dosed orally with [(14)C]1. PMID:19339375

Shaffer, Christopher L; Ryder, Tim F; Venkatakrishnan, Karthik; Henne, Ilana K; O'Connell, Thomas N

2009-07-01

292

Prevention of estradiol 17beta-D-glucuronide-induced canalicular transporter internalization by hormonal modulation of cAMP in rat hepatocytes.  

PubMed

In estradiol 17?-d-glucuronide (E17G)-induced cholestasis, the canalicular hepatocellular transporters bile salt export pump (Abcb11) and multidrug-resistance associated protein 2 (Abcc2) undergo endocytic internalization. cAMP stimulates the trafficking of transporter-containing vesicles to the apical membrane and is able to prevent internalization of these transporters in estrogen-induced cholestasis. Hepatocyte levels of cAMP are regulated by hormones such as glucagon and adrenaline (via the ?2 receptor). We analyzed the effects of glucagon and salbutamol (a ?2 adrenergic agonist) on function and localization of Abcb11 and Abcc2 in isolated rat hepatocyte couplets exposed to E17G and compared the mechanistic bases of their effects. Glucagon and salbutamol partially prevented the impairment in Abcb11 and Abcc2 transport capacity. E17G also induced endocytic internalization of Abcb11 and Abcc2, which partially colocalized with the endosomal marker Rab11a. This effect was completely prevented by salbutamol, whereas some transporter-containing vesicles remained internalized and mainly colocalizing with Rab11a in the perinuclear region after incubation with glucagon. Glucagon prevention was dependent on cAMP-dependent protein kinase (PKA) and independent of exchange proteins activated directly by cAMP (Epac) and microtubules. In contrast, salbutamol prevention was PKA independent and Epac/MEK and microtubule dependent. Anticholestatic effects of glucagon and salbutamol were additive in nature. Our results show that increases in cAMP could activate different anticholestatic signaling pathways, depending on the hormonal mediator involved. PMID:21865596

Zucchetti, Andrés E; Barosso, Ismael R; Boaglio, Andrea; Pellegrino, José M; Ochoa, Elena J; Roma, Marcelo G; Crocenzi, Fernando A; Sánchez Pozzi, Enrique J

2011-10-01

293

Influence of t-butylhydroquinone and beta-naphthoflavone on formation and transport of 4-methylumbelliferone glucuronide in Caco-2/TC-7 cell monolayers.  

PubMed

Human Caco-2 cells have been established as a model system for intestinal biotransformation and permeability. When grown on Transwell polycarbonate filters they develop morphologic and biochemical characteristics of enterocytes with well separated apical and basolateral surfaces. In addition, Caco-2/TC-7 cells have proven to be useful to study regulation of human UDP-glucuronosyltransferases (UGTs) by Ah receptor agonists and antioxidant-type inducers such as beta-naphthoflavone (BNF) and t-butylhydroquinone (TBHQ). In the present investigation, formation and transport of 4-methylumbelliferone glucuronide was studied in intact Caco-2 cell monolayers. The following results were obtained: when loaded with 50-200 microM MUF either apically or basolaterally, MUF-GA was the major metabolite which was mostly released (80%) at the basolateral surface, probably via the multidrug resistance protein isoform MRP3; MUF sulfate formation was low (5 +/-2%). Pretreatment of cells with 80 microM TBHQ or 50 microM BNF for 72 hr before addition of 100 microM MUF enhanced basolateral secretion of MUF-GA 1.4- and 1.7-fold, respectively. However, at >200 microM MUF, MUF-GA secretion and induction was smaller, probably due to inhibition of intracellular UGT activity. MRP3 protein was localized to the basolateral surface of Caco-2 cells but was not induced by TBHQ or BNF. The results suggest that MUF-GA is mostly secreted basolaterally in Caco-2 cell monolayers. Treatment with TBHQ or BNF significantly enhanced MUF-GA formation in the intact cell. PMID:11841785

Bock-Hennig, Barbara S; Kohle, Christoph; Nill, Karl; Bock, Karl Walter

2002-01-15

294

Determination of fatty acid ethyl esters in hair by GC-MS and application in a population of cocaine users.  

PubMed

A gas chromatography-mass spectrometry method for the determination of ethyl myristate, ethyl palmitate, ethyl oleate, and ethyl stearate in hair samples was developed, validated and applied to real samples. Ethyl myristate, ethyl palmitate, ethyl oleate, and ethyl stearate are fatty acid ethyl esters (FAEE) which are known to be direct biotransformation products of ethanol. Their presence in the body fluids and tissue is therefore indicative of alcohol intake and, in particular, FAEE concentration in hair higher than 0.5 ng/mg is indicative of excessive chronic alcohol consumption. The method was applied to 80 hair samples formerly found positive for cocaine and FAEE analytical results were compared with the presence of cocaethylene, a cocaine metabolite formed only when alcohol and cocaine are used together. According to our data the two biomarkers (FAEE and cocaethylene in hair) are tools of great value in the assessment of the diagnosis of use of cocaine and ethanol. In fact, discrepancies were noted and might be related to various factors including differences in consumption habits and thus permitting to distinguish the use of both substances non-concurrently or concurrently. Also, the determination of both markers may, in some cases, discriminate the use of moderate or heavy alcohol amounts when associated with cocaine. Finally, in a population of non-cocaine-users our results support FAEE as valuable means in the assessment of excessive alcohol chronic use. PMID:21159458

Politi, Lucia; Mari, Francesco; Furlanetto, Sandra; Del Bravo, Ester; Bertol, Elisabetta

2011-04-01

295

Performance of a composite membrane bioreactor for the removal of ethyl acetate from waste air.  

PubMed

Ethyl acetate removal from an air stream was carried out by using a flat composite membrane bioreactor. The composite membrane consisted of a dense polydimethylsiloxane top layer with an average thickness of 0.3 ?m supported in a porous polyacrylonitrile layer (50 ?m). The membrane bioreactor (MBR) was operated during 3 months, and a maximum elimination capacity of 225 g m?³ h?¹ at an empty bed residence time of 60s was observed. Removal efficiencies higher than 95% were obtained for inlet loads lower than 200 g m?³ h?¹ and empty bed residence times as short as 15 s. The estimated yield coefficient, determined from the carbon dioxide production, resulted in 0.82 g dry biomass synthesized per gram of ethyl acetate degraded. No data of ethyl acetate treatment in MBR have been found in the literature, but the results illustrate that membrane bioreactors can potentially be a good option for its treatment. PMID:21763129

Álvarez-Hornos, F J; Volckaert, D; Heynderickx, P M; Van Langenhove, H

2011-10-01

296

Characterization and antioxidant properties of six Algerian propolis extracts: ethyl acetate extracts inhibit myeloperoxidase activity.  

PubMed

Because propolis contains many types of antioxidant compounds such as polyphenols and flavonoids, it can be useful in preventing oxidative damages. Ethyl acetate extracts of propolis from several Algerian regions show high activity by scavenging free radicals, preventing lipid peroxidation and inhibiting myeloperoxidase (MPO). By fractioning and assaying ethyl acetate extracts, it was observed that both polyphenols and flavonoids contribute to these activities. A correlation was observed between the polyphenol content and the MPO inhibition. However, it seems that kaempferol, a flavonoid, contributes mainly to the MPO inhibition. This molecule is in a high amount in the ethyl acetate extract and demonstrates the best efficiency towards the enzyme with an inhibiting concentration at 50% of 4 ± 2 µM. PMID:24514562

Boufadi, Yasmina Mokhtaria; Soubhye, Jalal; Riazi, Ali; Rousseau, Alexandre; Vanhaeverbeek, Michel; Nève, Jean; Boudjeltia, Karim Zouaoui; Van Antwerpen, Pierre

2014-01-01

297

Molecular structure, thermal analysis and electrical properties of cyanoethyl and carbamoyl ethyl bagasse raw materials  

NASA Astrophysics Data System (ADS)

Infrared absorption spectra, thermal analysis as well as dielectric properties of cyano and carbamoyl ethylated bagasse raw materials and their hydrolysis with NaOH were studied. A new band appeared in the infrared spectra at 2252 cm -1, characteristic to cyano group and a new shoulder appeared at 3150 cm -1, characteristic to NH 2 of amide group for cyanoethyl and carbamoyl ethyl raw material, respectively. Also the band intensity at 1636 cm -1 characteristic of the amide group in the carbamoyl ethyl bagasse was found to be higher than that in case of bagasse raw material. A new band was seen at 1736 cm -1, characteristic to C=O of carboxyl group which formed due to hydrolysis of cyano or carbamoyl groups. The crystallinity indices of the produced bagasse derivative were calculated and the increase is attributed to cyano, carbamoyl and hydrolysis process. Incorporation of cyano group into bagasse increases its resistance against thermal degradation. So, loss in weight from TG curves under major decomposition temperature (350 °C) was about 59% for cyanoethyl bagasse raw material while it was about 69% at 350 °C for bagasse raw material and 60% for carbamoyl ethyl bagasse. A kinetic study of the thermal degradation process revealed that, bagasse and its derivatives followed a first order reaction and the degradation of derivatives was more complex. The dielectric constant ( ?') and AC electrical conductivity were studied with frequencies over the range (50-2000 Hz) for cyanoethylated, hydrolyzed cyanoethylated and carbamoyl ethylated bagasse raw material at two fixed temperatures (30 and 100 °C). Generally, the dielectric constant decreased and the conductivity increased with increasing frequencies. The increase in the nitrogen content in bagasse raw material due to cyanoethylation, carbamoyl ethylation and their hydrolysis cyanoethylated resulted in an increase in the dielectric constant.

Nada, A. M. A.; Seoudi, R.

2006-09-01

298

Diastereoselective Synthesis of a Strawberry Flavoring Agent by Epoxidation of Ethyl trans-b-Methylcinnamate  

NASA Astrophysics Data System (ADS)

The diastereoselective synthesis of ethyl (E)-3-methyl-3-phenylglycidate, a strawberry flavoring agent, is carried out by epoxidizing ethyl trans-b-methylcinnamate with m-chloroperbenzoic acid. This epoxidation is appropriate for the introductory organic laboratory and augments the small number of such experiments currently available for undergraduate education. In the course of performing this exercise, students are exposed to many important facets of organic chemistry such as synthesis, reaction mechanism, stereochemistry, chromatography, quantitative analysis, spectroscopy, and computational chemistry. The 1H NMR spectrum of this compound is especially interesting and presents instructive examples of diastereotopic protons and shielding effects of the aromatic ring current.

Pageau, Gayle J.; Mabaera, Rodwell; Kosuda, Kathryn M.; Sebelius, Tamara A.; Ghaffari, Ali H.; Kearns, Kenneth A.; McIntyre, Jean P.; Beachy, Tina M.; Thamattoor, Dasan M.

2002-01-01

299

Molecular Model of trans-3-(9-Anthryl)-2-Propenoic Acid Ethyl Ester  

NSDL National Science Digital Library

The Featured Molecules this month come from the paper by Nguyen and Weisman on solvent-free Wittig reactions and the stereochemical consequences of crowding in the transition state. The molecules include those pictured in the paper as well as the cis-isomer of 3-(9-anthryl)-2-propenoic acid ethyl ester. All structures were optimized at the B3LPY/6-31G* level. In the case of ethyl cinnamate, the cis-isomer is slightly more stable thermodynamically than the trans isomer, lending further support for the argument that the observed product distribution arises from the energetics of the transition state.

300

Laser vibrational overtone activation of ethyl acrylate/benzoyl peroxide mixture  

NASA Astrophysics Data System (ADS)

Intra- and extracavity laser vibrational overtone polymerization of ethyl acrylate/benzoyl peroxide mixture has been demonstrated. Five photolysis wavenumbers on and near the fifth CH stretch overtone absorption of benzoyl peroxide was investigated. The polymer yield was monitored by observing the decrease in the intensity ratio of the olefinic/methyl and methylenic first CH stretch overtone absorptions of ethyl acrylate. The rate of the polymerization did not depend on the photolysis wavenumber. Molecular weights of the overtone initiated polymers were an order of magnitude larger than those obtained by thermal polymerization. The polymerization rate is compared to the intracavity laser vibrational overtone polymerization of methyl methacrylate.

Grinevich, Oleg; Snavely, D. L.

1999-04-01

301

4?-Chloro-biphenyl-3-yl 2,2,2-trichloro-ethyl sulfate  

PubMed Central

The title compound, C14H10Cl4O4S, is a 2,2,2-trichloro­ethyl-protected precursor of 4?-chloro­biphenyl-3-yl sulfate, a sulfuric acid ester of 4?-chloro­biphenyl-3-ol. The Caromatic—O and O—S bond lengths of the Caromatic—O—S unit are comparable to those in structurally analogous biphenyl-4-yl 2,2,2-trichloro­ethyl sulfates with no electro­negative chlorine substituent in the benzene ring with the sulfate ester group. The dihedral angle between the aromatic rings is 27.47?(6)°. PMID:21588655

Li, Xueshu; Parkin, Sean; Duffel, Michael W.; Robertson, Larry W.; Lehmler, Hans-Joachim

2010-01-01

302

On the inhibition of AHAS by chlorimuron ethyl: A theoretical study  

NASA Astrophysics Data System (ADS)

The reaction between chlorimuron ethyl (CE) herbicide and the HEThDP- intermediate is addressed with the tools of computational chemistry, molecular dynamics and quantum chemistry, in order to check the postulated hypothesis that the inhibition of AHAS could proceed via a nucleophilic aromatic substitution reaction between HEThDP- and chlorimuron ethyl. The obtained results agree well with the empirical evidence for the inhibition process of AHAS by sulfonylureas, supporting the idea that the inhibition process could proceed by this via. It is also found that the nucleophilic attack of the C? of the intermediate on the ipso carbon of the herbicide pyrimidinic ring is the rate-limiting step.

Jaña, Gonzalo A.; Alderete, Joel B.; Delgado, Eduardo J.

2011-11-01

303

40 CFR 721.10075 - Carbon black, 4-[[2-(Sulfooxy) ethyl]substituted] phenyl- modified, sodium salts (generic).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Carbon black, 4-[[2-(Sulfooxy) ethyl]substituted...Chemical Substances § 721.10075 Carbon black, 4-[[2-(Sulfooxy) ethyl]substituted...substance identified generically as carbon black, 4-[[2-(Sulfooxy)...

2010-07-01

304

On using film boiling to thermally decompose liquid organic chemicals: Application to ethyl acetate as a model compound  

E-print Network

On using film boiling to thermally decompose liquid organic chemicals: Application to ethyl acetate 21 August 2013 Keywords: Film boiling Thermal decomposition Pyrolysis Ethyl acetate Critical heat flux (CHF) Leidenfrost point a b s t r a c t Film boiling on a horizontal tube is used to study

Walter, M.Todd

305

Interaction of Ethyl Chloride with Amorphous Solid Water Thin Film on Ru(001) and O/Ru(001) Surfaces  

E-print Network

, as indicated by work function change measurements. P-TPD from clean Ru(001) surface reveals a completeInteraction of Ethyl Chloride with Amorphous Solid Water Thin Film on Ru(001) and O/Ru(001Vised Manuscript ReceiVed: April 11, 2009 The adsorption of ethyl chloride (EC) on clean and oxygen covered Ru(001

Asscher, Micha

306

Small angle neutron scattering study of deuterated sodium dodecylsulfate micellization in dilute poly((2edimethylamino)ethyl methacrylate) solutions  

E-print Network

Small angle neutron scattering study of deuterated sodium dodecylsulfate micellization in dilute 2010 Keywords: Poly((2edimethylamino)ethyl methacrylate) Micelle Small angle neutron scattering a b angle neutron scattering. We found three transitions of the poly ((2edimethylamino)ethyl methacrylate

Kofinas, Peter

307

Quercetin-3-O-glucuronide inhibits noradrenaline-promoted invasion of MDA-MB-231 human breast cancer cells by blocking ??-adrenergic signaling.  

PubMed

Endogenous catecholamines such as adrenaline (A) and noradrenaline (NA) are released from the adrenal gland and sympathetic nervous system during exposure to stress. The adrenergic system plays a central role in stress signaling, and excessive stress was found to be associated with increased production of reactive oxygen species (ROS). Overproduction of ROS induces oxidative damage in tissues and causes the development of diseases such as cancer. In this study, we investigated the effects of quercetin-3-O-glucuronide (Q3G), a circulating metabolite of quercetin, which is a type of natural flavonoid, on the catecholamine-induced ?2-adrenergic receptor (?2-AR)-mediated response in MDA-MB-231 human breast cancer cells expressing ?2-AR. Treatment with A or NA at concentrations above 1?M generated significant levels of ROS, and NA treatment induced the gene expression of heme oxygenase-1 (HMOX1), and matrix metalloproteinase-2 (MMP-2) and -9 (MMP9). Inhibitors of p38 MAP kinase (SB203580), cAMP-dependent protein kinase (PKA) (H-89), activator protein-1 (AP-1) transcription factor (SR11302), and NF-?B and AP-1 (Tanshinone IIA) decreased MMP2 and MMP9 gene expression. NA also enhanced cAMP induction, RAS activation and phosphorylation of ERK1/2. These results suggested that the cAMP-PKA, MAPK, and ROS-NF-?B pathways are involved in ?2-AR signaling. Treatment with 0.1?M Q3G suppressed ROS generation, cAMP and RAS activation, phosphorylation of ERK1/2 and the expression of HMOX1, MMP2, and MMP9 genes. Furthermore, Q3G (0.1?M) suppressed invasion of MDA-MB-231 breast cancer cells and MMP-9 induction, and inhibited the binding of [(3)H]-NA to ?2-AR. These results suggest that Q3G may function to suppress invasion of breast cancer cells by controlling ?2-adrenergic signaling, and may be a dietary chemopreventive factor for stress-related breast cancer. PMID:24929186

Yamazaki, Shunsuke; Miyoshi, Noriyuki; Kawabata, Kyuichi; Yasuda, Michiko; Shimoi, Kayoko

2014-09-01

308

CYTOGENETIC STUDIES OF ETHYL ACRYLATE USING C57BL/6 MICE  

EPA Science Inventory

The clastogenicity of ethyl acrylate (EA) was examined in vivo by injecting i.p. 5 male C57BL/6 mice per dose group with either 125, 250, 500, 1000 mg/kg EA dissolved in saline. wenty-four hours after injection, the animals were anesthetized, the spleens aseptically removed, and ...

309

Dampness and 2Ethyl1-hexanol in Floor Construction of Rehabilitation Center: Health Effects in Staff  

Microsoft Academic Search

The authors evaluated changes of symptoms and biomarkers in health care staff (N = 18) for people with different physical dysfunctions and similarly in an external office control group in a nondamp building (N = 15). The first workplace had verified dampness in the floor construction, with formation of 2-ethyl-1-hexanol from water-based glue. Tear film break up time (BUT), nasal

Gunilla Wieslander; Anders Kumlin; Dan Norbäck

2010-01-01

310

Coherent Electronic and Nuclear Dynamics for Charge Transfer in 1-Ethyl-4-(carbomethoxy)pyridinium Iodide  

E-print Network

iodine. Nuclear relaxation of the acceptor induces sub-picosecond decay of the pump-probe polarization charge transfer between iodide and 1-ethyl-4-(carbomethoxy)- pyridinium ions. Pump-probe signal yields unique information on transient material resonances located outside the laser pulse spectrum

Scherer, Norbert F.

311

IRIS TOXICOLOGICAL REVIEW AND SUMMARY DOCUMENTS FOR TERTIARY AMYL ETHYL ETHER (TAEE)  

EPA Science Inventory

This is EPA's first assessment of the noncancer health effects and carcinogenic potential of tertiary amyl ethyl ether (TAEE). The IRIS program is preparing an assessment that will incorporate health effects information available for TAEE, and current risk assessment methods. T...

312

Ethyl Chloride as an Antipruritic Agent: A Double-Blind Placebo-Controlled Prospective Study  

Microsoft Academic Search

Background: Ethyl chloride (EC) is usually used as a topical anesthetic spray agent. However, its antipruritic effects have never been studied, to the best of our knowledge. Methods: A double-blind placebo-controlled prospective study. Overall, 51 healthy volunteers underwent a histamine skin prick test on both arms in order to trigger local pruritus. Thereafter, the affected areas were treated with an

Amir Gal-Oz; Ori Rogowski; Michael Swartzon; Shmuel Kivity

2010-01-01

313

Comparative toxicity of tetra ethyl lead and lead oxide to earthworms, Eisenia fetida (Savigny)  

Microsoft Academic Search

Leaded gasoline contains tetra ethyl lead (TEL) as an antiknocking agent, which produces major amounts of lead oxide in automobile exhaust along with traces of TEL. To minimize the lead contamination, methyl tertiary butyl ether (MTBE) is used as a substitute for producing unleaded gasoline. It has become increasingly apparent that young children are highly susceptible to the harmful effects

J Venkateswara Rao; P Kavitha; A Padmanabha Rao

2003-01-01

314

Biodegradation of chlorimuron-ethyl by the bacterium Klebsiella jilinsis 2N3.  

PubMed

Enrichment culturing of sludge taken from an industrial wastewater treatment pond led to the identification of a bacterium (Klebsiella jilinsis H. Zhang) that degrades chlorimuron-ethyl with high efficiency. Klebsiella jilinsis strain 2N3 grows with chlorimuron-ethyl as the sole nitrogen source at the optimal temperature range of 30-35 degrees C and pH values between 6.0-7.0. In liquid medium, the degradation activity was further induced by chlorimuron-ethyl. Degradation rates followed the pesticide degradation kinetic equation at concentrations between 20 and 200 mg L(-1). Using initial concentrations of 20 and 100 mg L(-1), the degradation rates of chlorimuron-ethyl were 83.5 % and 92.5 % in 12 hours, respectively. At an initial concentration higher than 200 mg L(-1), the degradation rate decreased slightly as the concentration increased. The 2N3 strain also degraded the sulfonylurea herbicides ethametsulfuron, metsulfuron-methyl, nicosulfuron, rimsulfuron, and tribenuron-methyl. This study provides scientific evidence and support for the application of K. jilinsis in bioremediation to reduce environmental pollution. PMID:20574870

Zhang, Hao; Zhang, Xianghui; Mu, Wenhui; Wang, Jiaxiu; Pan, Hongyu; Li, Yu

2010-08-01

315

An unusual source for postmortem findings of methyl ethyl ketone and methanol in two homicide victims.  

PubMed

Contamination from methyl ethyl ketone and methanol utilized in a new technique to visualize fingerprints on human skin was detected postmortem in blood and vitreous humor by toxicological analysis. Two cases which represent the first field trials of the fingerprinting technique in Canada are presented. Details of the toxicological analyses and the nature of the contamination are discussed. PMID:8082857

Caughlin, J D

1994-06-28

316

IRIS TOXICOLOGICAL REVIEW OF METHYL ETHYL KETONE [AND IRIS SUMMARY] (EXTERNAL REVIEW DRAFT)  

EPA Science Inventory

The U.S. EPA has conducted an external peer review of the scientific basis supporting the health hazard and dose-response assessment for methyl ethyl ketone that will appear on the Agency's online data base, the Integrated Risk Information System (IRIS). Peer review is meant to ...

317

Preparation and Structures of Ethyl-Cyanoethyl Cellulose/Cross-Linked Polystyrene Composites.  

National Technical Information Service (NTIS)

Ethyl-cyanoethyl cellulose ((E-CE)C)/cross-linked polystyrene (PS) composites were prepared via polymerization of styrene in (E-CE)C/styrene solutions with glycol diacrylate as a cross-linking reagent. The polymerization of the solution, morphology, and m...

S. H. Jiang, Y. Huang

1995-01-01

318

Effect of Aquilegia vulgaris (L.) ethyl ether extract on liver antioxidant defense system in rats  

Microsoft Academic Search

Introduction: The ethyl ether extract from Aquilegia vulgaris (L.) (Ranunculaceae) contains a lot of phenolic acids. Their hydroxyl groups are capable of donating hydrogen atoms at the initial stage of lipid peroxidation (LPO), which inactivates hydroxyperoxides formed from polyunsaturated fatty acids (PUFAs) and leads to breakdown of the propagation chain. Material and methods: Rats pretreated with acetaminophen (APAP) (600 mg\\/kg

Ma?gorzata Ewertowska; Jadwiga Jodynis-Liebert; Ma?gorzata Kujawska; Teresa Adamska; Irena Mat?awska; Miros?awa Szaufer-Hajdrych

2009-01-01

319

Fatty acid ethyl esters, nonoxidative ethanol metabolites, synthesis, uptake, and hydrolysis by human platelets.  

PubMed

The consumption of alcohol is known to have both positive and negative effects on the functioning of the cardiovascular system in general, and on platelet function in particular. Fatty acid ethyl esters (FAEEs) are non-oxidative metabolite of ethanol that may mediate the ethanol effect on platelet function leading to either bleeding or clotting. The aim of the current study was to investigate the synthesis, uptake, and hydrolysis of FAEEs by human platelets. Isolated platelets were incubated with ethanol for various times, and FAEE synthesis were measured by gas chromatography mass-spectrometry (GC-MS). In addition, platelets were incubated with (14)C-ethyl oleate, and FAEE uptake and hydrolysis were measured. There was significant synthesis of FAEEs by human platelets within 30 min of exposure to ethanol. The major FAEE species formed by human platelets exposed to ethanol were ethyl palmitate and ethyl stearate. FAEE uptake by human platelets showed maximum uptake by 60 s. The majority of FAEEs (50-80%) incorporated into platelets remained intact for up to 10 min. FAEE hydrolysis led to an increase in free fatty acids, with minimal subsequent esterification of the free fatty acids into phospholipids, triglycerides, and cholesterol esters. These studies show that FAEEs, non-oxidative metabolite of ethanol, can be incorporated into, synthesized, and hydrolyzed by human platelets. PMID:16325465

Salem, Raneem O; Cluette-Brown, Joanne E; Laposata, Michael

2005-12-30

320

Hepatoprotective activity of leaves of Cassia occidentalis against paracetamol and ethyl alcohol intoxication in rats  

Microsoft Academic Search

Cassia occidentalis L. (Caesalpiniaceae), commonly known as ‘Kasondi’, is used in Unani medicine for liver ailments and is an important ingredient of several polyherbal formulations marketed for liver diseases. The hepatoprotective effect of aqueous-ethanolic extract (50%, v\\/v) of leaves of kasondi was studied on rat liver damage induced by paracetamol and ethyl alcohol by monitoring serum transaminase (aspartate amino transferase

M. A Jafri; M. Jalis Subhani; Kalim Javed; Surender Singh

1999-01-01

321

Synthesis of antibacterial polymers from 2-dimethylamino ethyl methacrylate quaternized by dimethyl sulfate  

Microsoft Academic Search

An antibacterial quaternary ammonium acrylic monomer (1) was synthesized by quaternization of 2-dimethylamino ethyl methacrylate with dimethyl sulfate. This synthetic route to quaternary ammonium salt monomer proved to be of high yield and lower cost than that used to synthesize alkyl halide. The corresponding homopolymers (2) were then obtained by free radical polymerization using potassium persulfate as the initiator. The

Huajiang Zuo; Dingcai Wu; Ruowen Fu

2010-01-01

322

Neurotoxicity Associated with Occupational Exposure to Acetone, Methyl Ethyl Ketone, and Cyclohexanone  

Microsoft Academic Search

The neurotoxic effects of acetone, methyl ethyl ketone (MEK), and cyclohexanone on Romanian workers and the impact of those effects on industry environmental standards have been controversial subjects. To scientifically substantiate the standards, a study was conducted on three groups of workers to determine the changes induced by ketone solvents on the central and peripheral nervous systems. Groups of exposed

E. Mitran; T. Callender; B. Orha; P. Dragnea; G. Botezatu

1997-01-01

323

Sequencing batch biofilter operation for treatment of methyl ethyl ketone (MEK) contaminated air.  

PubMed

Biofiltration is increasingly used as a method for decontaminating gas streams containing low concentrations of biodegradable volatile organic compounds. In typical biofilter installation control is quite passive and is often restricted to adjustment of the medium's moisture content or nutrient supply. Although inexpensive, such operation limits implementation of engineering decisions that could improve performance during normal operation orallow effective handling of the short-term variations in the waste stream typical of industrial operations. This paper describes how sequencing batch operation can be applied to biofilters designed and operated as controlled, unsteady-state, periodic processes for the destruction of gas-phase contaminants. In the studies described herein, the impact of sequencing batch operation was assessed in a methylethyl ketone degrading biofilter over a 130-day period. The biofilter was packed with a polyurethane foam medium that contained activated carbon. Methyl ethyl ketone and carbon dioxide concentrations were monitored during both normal steady loading conditions and short-term, unsteady-state transient loading conditions (i.e., shock loading). A gas stream containing 106 ppm, methyl ethyl ketone was used for normal loading studies, and several model shock loads consisting of 530 ppm, methyl ethyl ketone for a duration of one hour were used to assess system response to transient loads. Data are presented which clearly demonstrate that sequencing batch operation can be successfully applied to biofilters treating methyl ethyl ketone contaminated air streams. Such operation can increase an operator's ability to minimize contaminant emission during transient periods of elevated contaminant loading. PMID:12803246

Li, C; Moe, W M

2003-05-01

324

nanodroplet water imbibed in poly(2-hydroxy-ethyl-methacrylate) (polyHEMA) near its glass  

E-print Network

nanodroplet water imbibed in poly(2-hydroxy- ethyl-methacrylate) (polyHEMA) near its glass times are also Arrhenius in character and faster than the relaxation responsible for the glass transition. The second is the convergence of extrapo- lated binary solution Tg to the temperature 138 2 K (7

Kansas, University of

325

Dose-dependent stimulation of hepatic retinoic acid hydroxylation/oxidation and glucuronidation in brook trout, Salvelinus fontinalis, after exposure to 3,3{prime}, 4,4{prime}-tetrachlorobiphenyl  

SciTech Connect

Extremely low stores of vitamin A have been reported in fish and birds inhabiting regions contaminated by coplanar polychlorinated biphenyls (PCBs) and other organochlorines, suggesting many possible effects on retinoid biochemical pathways. Metabolic imbalances associated with biologically active retinoids (e.g., retinoic acid) could be associated with tetratogenesis, edema, growth inhibition, reproductive impairment, immunosuppression, and susceptibility to cancer. Sexually mature brook trout were injected imtraperitoneally with the coplanar PCB 3,3{prime}, 4,4{prime}-tetrachlorobiphenyl (TCBP) and again 4 weeks later. At 8 weeks, retinoic acid metabolism was measured in liver microsomes. To the authors' knowledge, retinoic acid conjugation by UDP-glucuronyltransferase is described here for the first time in fish. A substantial rate of glucuronidation was detected in the microsomes from control brook trout, which tended to increase over the dose range of TCBP. Glucuronidation was significantly greater in fish receiving the 10 {micro}g/g body weight dose level. Metabolism through the cytochrome P450 system was also dose-dependent, resulting in significantly greater production of 4-hydroxyretinoic acid at the 10 {micro}g/g dose level. In contrast, subsequent oxidation to 4-oxo-retinoic acid was greatest at the 1 {micro}g/g dose level and did not increase further at higher doses. Liver stores of dehydroretinyl palmitate/oleate were significantly decreased at the 5 and 10 {micro}g/g dose levels.

Boyer, P.M.; Ndayibagira, A.; Spear, P.A.

2000-03-01

326

Detection of chlorpyrifos-ethyl (Dursban) and its metabolites in urine samples using immunoassays with confirmation by gas chromatography/mass spectrometry  

E-print Network

Chlorpyrifos-ethyl (Dursban) belongs to the organophosphate class of pesticides. Many organophosphates, such as parathion and chlordane, are highly toxic and have restricted usage. Others, including chlorpyrifos-ethyl, are widely used for domestic...

Clewis, Suenda Beth

2012-06-07

327

Ethyl pyruvate reduces ventilation-induced neutrophil infiltration and oxidative stress.  

PubMed

Mechanical ventilation with high tidal volume causes intense inflammatory responses and oxidative stress, including the release of high-mobility group box-1 (HMGB1), plasminogen activator inhibitor-1 (PAI-1) and heme oxygenase-1 (HO-1). The mechanisms regulating ventilator-induced lung injury (VILI) are unclear. We hypothesized that ethyl pyruvate attenuated acute lung injury as adjunctive pharmacological strategy by down-regulating neutrophil infiltration, oxidative stress and HMGB1 mRNA expression. C57BL/6 mice, weighing 20-25 g, were exposed to either low-tidal-volume (6 mL/kg) or high-tidal-volume (30 mL/kg) mechanical ventilation with room air for 2-5 h and subjected to 100 mg/kg ethyl pyruvate administration intraperitoneally. Non-ventilated mice served as the control group. Evans blue dye, lung wet-to-dry weight ratio, lung neutrophil infiltration and myeloperoxidase, free radicals, gene expression of HMGB1, active PAI-1 and HMGB1 production and HO-1 expression were measured. The expression of HO-1 was studied by immunohistochemistry. High-tidal-volume ventilation induced microvascular leak, neutrophil recruitment, oxidative injury, HMGB1 and active PAI-1 protein production, and upregulation of HMGB1 mRNA and stress-inducible protein HO-1. In contrast, administration of ethyl pyruvate before high stretch mechanical ventilation prevented lung edema formation, inflammatory cytokine production, neutrophil accumulation, oxidative stress and HMGB1 and HO-1 expression. High-tidal-volume mechanical ventilation increased microvascular permeability, neutrophil influx and inflammatory cytokines. Ethyl pyruvate is capable of suppressing the VILI related to the reduction of HMGB1 and our findings support the potential use of ethyl pyruvate as a therapeutic agent for the prevention of VILI. PMID:22715434

Li, Li-Fu; Kao, Kuo-Chin; Yang, Cheng-Ta; Huang, Chung-Chi; Liu, Yung-Yang

2012-06-01

328

40 CFR 721.5375 - Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter, bis-[[[[(sub-sti-tut-ed)] amino]-alkyl-phenyl...  

...2014-07-01 false Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter, bis...721.5375 Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter, bis...chemical substance ni-tro-thio-phene-car-boxy-lic acid, ethyl ester,...

2014-07-01

329

40 CFR 721.5375 - Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter, bis-[[[[(sub-sti-tut-ed)] amino]-alkyl-phenyl...  

Code of Federal Regulations, 2010 CFR

...Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter...sub-sti-tut-ed)] amino]-alkyl-phenyl...Ni-tro-thio-phene-car-boxy-lic acid, ethyl es-ter...sub-sti-tut-ed)] amino]-alkyl-phenyl...ni-tro-thio-phene-car-boxy-lic acid, ethyl ester,...

2010-07-01

330

Comparison of the delayed neurotoxicity of O?methyl and O?ethyl analogs of EPN, leptophos, and cyanofenphos  

Microsoft Academic Search

Eight pairs of O?methyl and O?ethyl O?(substituted?phenyl) phenylphosphonothionates were evaluated with respect to their delayed neurotoxic activity in hens. O?methyl compounds were in all cases more active than their O?ethyl analogs. The neurotoxic potential of the O?methyl phenylphosphonothionates was 2,5?diCl >4?NO2 >2,4,5?triCl and 2,4,6?triCl >2,4?diCl >2,5?diCl?4?Br >4?CN, when single oral doses were given. Both EPN?ethyl and leptophos?raethyl were more neurotoxic

B. Magnus Francis; Larry G. Hansen; Robert A. Metcalf; Robert L. Metcalf

1982-01-01

331

Dynamics Simulations and Statistical Modeling of Thermal Decomposition of 1-Ethyl-3-methylimidazolium Dicyanamide and 1-Ethyl-2,3-dimethylimidazolium Dicyanamide.  

PubMed

Quasi-classical, direct dynamics trajectories were calculated at the B3LYP/6-31G* level of theory, in an attempt to understand decomposition mechanisms of 1-ethyl-3-methylimidazolium dicyanamide (EMIM(+)DCA(-)) and 1-ethyl-2,3-dimethylimidazolium dicyanamide (EMMIM(+)DCA(-)). The trajectories showed many dissociation paths for these two ionic liquids. Using trajectory results as a guide, structures of transition states and products that might be important for decomposition of these two compounds were determined using density functional theory calculations. Rice-Ramsperger-Kassel-Marcus (RRKM) theory was then utilized to examine properties of energized ionic liquids and to determine unimolecular rates for crossing various transition states. On the basis of RRKM modeling, initial decomposition paths for energized EMIM(+)DCA(-) correspond to formation of an N-heterocyclic carbene and acid pair via transfer of the C2 proton of EMIM(+) to DCA(-), and evolution of methylimidazole and ethylimidazole via SN2 alkyl abstraction by DCA(-). Similar decomposition paths were identified for energized EMMIM(+)DCA(-), except that the reactivity of C2 of the imidazolium cation is significantly reduced upon substitution of a methyl group for a hydrogen atom at this position. The present work demonstrates that dynamics simulations, in conjunction with statistical modeling, are able to provide insight into decomposition mechanisms, kinetics, and dynamics for alkylimidazolium-based ionic liquids and to predict product branching ratios and how they vary with decomposition temperatures. PMID:25275818

Liu, Jianbo; Chambreau, Steven D; Vaghjiani, Ghanshyam L

2014-11-26

332

Alternanthera sessilis Red Ethyl Acetate Fraction Exhibits Antidiabetic Potential on Obese Type 2 Diabetic Rats.  

PubMed

The antidiabetic potential of Alternanthera sessilis Red was investigated using the obese type 2 diabetic rats induced by high fat diet and streptozotocin. Three fractions (hexane, ethyl acetate, and water) were obtained from the crude ethanol extract of Alternanthera sessilis Red. Alternanthera sessilis Red ethyl acetate fraction (ASEAF) was found to possess the most potent antihyperglycemic effect through oral glucose tolerance test. The ASEAF was subsequently given to the diabetic rats for two weeks. It was found that two-week administration of ASEAF reduces the fasting blood glucose level, triglyceride level, and free fatty acid level of the rats. ASEAF-treated diabetic rats showed higher pancreatic insulin content and pancreatic total superoxide dismutase activity compared to the untreated diabetic rats. Also, the insulin sensitivity indexes suggested that ASEAF ameliorates the insulin resistant state of the diabetic rats. In conclusion, ASEAF could be developed into a potential antidiabetic agent for the management of type 2 diabetes. PMID:23606892

Tan, Kok Keong; Kim, Kah Hwi

2013-01-01

333

Synthesis and immunomodulatory activites of new 5-hydrazino-3-methyl-4-isothiazolecarboxylic acid ethyl esters.  

PubMed

Several new derivatives of 5-hydrazino-3-methyl-4-isothiazolecarboxylic ethyl esters were synthesized. Using 4-aminoacetophenone, the hydrazine group was transformed in position 5 in the hydrazone which reacted with the isocyanates, aldehydes and sugars. Thirteen newly synthesized compounds were tested for their ability to affects the immunological response in vitro in several rodent models. The immunoregulatory properties of the compounds were differential and dose-dependent. The strongest activity was exhibited by 5-{N'-[1-4{-4-[3-(-methoxyphenyl)-ureidol]-phenylethylidene]-hydrazino}-3-methyl-4-isothiazolecarboxylic acid ethyl ester (compound 3a). The compound strongly inhibited the secondary, humoral immune response to sheep erythrocytes and the proliferative response of mouse splenocytes to concanavalin A and pokeweed mitogen. The immunotropic activities of the new isothiazole derivatives and potential application of the compounds in therapy are discussed. PMID:19894646

Lipnicka, Urszula; Maczy?ski, Marcin; Artym, Jolanta; Zimecki, Micha?

2009-01-01

334

An Evaluation of Ethyl Silicate-Based Grouts for Weathered Silicate Stones  

NASA Astrophysics Data System (ADS)

Culturally significant monuments made of weathered siliceous stone often display sub-surface condition issues such as cracks and voids. These issues require grouts that are ideally compatible with the composition and properties of the substrate. Based on the successful application of ethyl silicates as consolidants in recent literature, this study examines possible formulation pathways for the development of a grout incorporating ethyl silicate. Tetraethylorthosilicate (TEOS), dibutyltin dilaurate (DBTL) as a catalyst, silicone oil (PDMS), various grades of ground quartz, sepiolite, and hollow glass spheres were used in differing concentrations to create samples. These were visually and physically assessed on workability, separation, shrinkage, cracking, strength, and flexibility. Quantitative analysis was performed on selected formulations using UV-Vis-NIR reflectance spectroscopy in coordination with a weight loss experiment to investigate kinetics, dynamic mechanical analysis (DMA), and scanning electron microscopy (SEM). Successful formulations tended to include oligomeric TEOS, crushed quartz of mixed grades, sepiolite powder, and PDMS, and show promise for future investigations.

Dolph, Brittany Helen

335

Lipase-catalysed kinetic resolution of ethyl D,L-2-amino-4-phenylbutyrate by hydrolysis  

Microsoft Academic Search

Of 25 commercial lipases, nine were able to catalyse the hydrolysis of ethyl D,L-2-amino-4-phenylbutyrate (D,L-APBAE) to optically active D-APBAE, an intermediate for the synthesis of inhibitors of angiotensin-converting enzyme, with specific selectivity ranging between 3.7 and 12.5. Optimal conditions for porcine pancrease lipase-catalyzed reaction gave a 68% conversion and the D-ester was obtained by a simple extraction with an optical

Jer-Yiing Houng; Chung-Lung Hsieh; Shui-Tein Chen

1996-01-01

336

Potential preservation of native American petroglyphs at Steamboat Butte, Montana, using ethyl silicate solution treatments  

USGS Publications Warehouse

Samples of the Tongue River Sandstone, collected from the top of Steamboat Butte in central Montana, were treated with an ethyl silicate solution. The samples showed a large increase in compressive strength and freeze-thaw resistance, relative to untreated samples, and indicates the treatment(s) significantly consolidate(s) the stone, thus providing a method to increase the lifetime of the petroglyphs carved onto the stone.

Grisafe, D.A.

2002-01-01

337

Induction of HL60 apoptosis by ethyl acetate extract of Cordyceps sinensis fungal mycelium  

Microsoft Academic Search

The cultivated mycelium of a Cordyceps sinensis (Cs) fungus was sequentially extracted by petroleum ether, ethyl acetate (EtOAc), ethanol and water. The EtOAc extract showed the most potent cytotoxic effect against the proliferation of human premyelocytic leukemia cell HL-60, with an ED50 ? 25 ?g\\/ml for 2-day treatment. The EtOAc extract induced the characteristic apoptotic symptoms in the HL-60 cells,

Qiaoxia Zhang; Jianyong Wu; Zongding Hu; Duan Li

2004-01-01

338

Sustained Release of Amoxicillin from Ethyl Cellulose-Coated Amoxicillin\\/Chitosan–Cyclodextrin-Based Tablets  

Microsoft Academic Search

Sustained release mucoadhesive amoxicillin tablets with tolerance to acid degradation in the stomach were studied. The sustained-release\\u000a tablets of amoxicillin were prepared from amoxicillin coated with ethyl cellulose (EC) and then formulated into tablets using\\u000a chitosan (CS) or a mixture of CS and beta-cyclodextrin (CD) as the retard polymer. The effects of various (w\\/w) ratios of EC\\/amoxicillin, the particle sized

Kultida Songsurang; Jatuporn Pakdeebumrung; Narong Praphairaksit; Nongnuj Muangsin

2011-01-01

339

Utilization of ethyl ester of waste vegetable oils as fuel in diesel engines  

Microsoft Academic Search

Jordan relies heavily on expensive and unreliable imported oil. Therefore, this study was initiated to investigate the potential of ethyl ester used as vegetable oil (VO; biodiesel) to substitute oil-based diesel fuel. The fuels tested were several ester\\/diesel blends including 100% ester in addition to diesel fuel, which served as the baseline fuel. Variable-speed tests were run on all fuels

Mohamad I Al-Widyan; Ghassan Tashtoush; Moh'd Abu-Qudais

2002-01-01

340

The effects of ethyl methanesulfonate treatment on Eucalyptus pollen behaviour in vitro  

Microsoft Academic Search

Treating pollen with mutagens prior to controlled pollination may facilitate the production of mutant trees for developmental\\u000a studies and eventual plantation improvement. To establish a suitable dose of the chemical mutagen ethyl methanesulfonate (EMS)\\u000a for the testing of this hypothesis, pollen of Eucalyptus globulus ssp. globulus and E. grandis was studied in vitro. Pollen germination, pollen tube elongation and generative

L. J. McManus; J. Sasse; C. K. Blomstedt; G. Bossinger

2007-01-01

341

Performance of a composite membrane bioreactor for the removal of ethyl acetate from waste air  

Microsoft Academic Search

Ethyl acetate removal from an air stream was carried out by using a flat composite membrane bioreactor. The composite membrane consisted of a dense polydimethylsiloxane top layer with an average thickness of 0.3?m supported in a porous polyacrylonitrile layer (50?m). The membrane bioreactor (MBR) was operated during 3months, and a maximum elimination capacity of 225gm?3h?1 at an empty bed residence

F. J. Álvarez-Hornos; D. Volckaert; P. M. Heynderickx; H. Van Langenhove

2011-01-01

342

DFT NORMAL MODES ON TMS+ ADDUCT OF sec-BUTYL ETHYL KETONE  

E-print Network

DFT NORMAL MODES ON TMS+ ADDUCT OF sec-BUTYL ETHYL KETONE Copyright 2001 T.H. Morton, University. ********************************************* Gaussian 98: x86-Win32-G98RevA.7 11-Apr-1999 17-Nov-2001 ********************************************* %chk=etmechcoetTMS,9=2,10=2,18=1,28=1/1; 7/8=1,10=1,25=1/1,2,3,16; 1/10=4,30=1/3; 99/6=100/99; ------------------------------------- TMS

Morton, Thomas Hellman

343

Ethyl-Eicosapentaenoic Acid in First-Episode Psychosis. A 1H-MRS Study  

Microsoft Academic Search

Ethyl-eicosapentaenoic acid (E-EPA) is an omega-3 fatty acid that has been used in a range of neuropsychiatric conditions with some benefits. However, its mechanism of action is unknown. Here, we investigate its effects on in vivo brain metabolism in first-episode psychosis (FEP). Proton magnetic resonance spectroscopy at 3 T was performed in the temporal lobes of 24 FEP patients before

Gregor E Berger; Stephen J Wood; R Mark Wellard; Tina M Proffitt; Mirabel McConchie; G Paul Amminger; Graeme D Jackson; Dennis Velakoulis; Christos Pantelis; Patrick D McGorry

2008-01-01

344

Methyl and ethyl soybean esters as renewable fuels for diesel engines  

Microsoft Academic Search

The primary problems associated with using straight soybean oil as a fuel in a compression ignition internal combustion engine\\u000a are caused by high fuel viscosity. Transesterification of soybean oil with an alcohol provides a significant reduction in\\u000a viscosity, thereby enhancing the physical properties of the renewable fuel to improve engine performance. The ethyl and methyl\\u000a esters of soybean oil with

S. J. Clark; L. Wagner; M. D. Schrock; P. G. Piennaar

1984-01-01

345

Highly Enantioselective Organocatalytic Addition of Ethyl Trifluoropyruvate to Ketones with Subzero Temperature Microwave Activation  

Microsoft Academic Search

An enantioselective organocatalytic microwave-assisted method for the addition of ethyl trifluoropyruvate to ketones to synthesize\\u000a highly enantiomerically enriched organofluorine synthons is described. Besides the high yields, diastereo- and enantioselectivities,\\u000a the most important observation is that the use of microwave irradiation at subzero temperatures proved to be beneficial. The\\u000a results indicate that subzero temperature microwave chemistry is a potentially intriguing tool

Shainaz M. Landge; Béla Török

2009-01-01

346

Influence of moisture on the crystal forms of niclosamide obtained from acetone and ethyl acetate  

Microsoft Academic Search

The purpose of this study was to elucidate the formation of crystal hydrates of niclosamide and to delineate the effect of\\u000a relative humidity on the crystal forms obtained from acetone and ethyl acetate. Recrystallization of niclosamide was performed\\u000a in the presence and absence of moisture. Two hydrates and their corresponding anhydrates were isolated. The hydrates obtained\\u000a by the process of

Rahul V. Manek; William M. Kolling

2004-01-01

347

Accurate Spectroscopic Characterization of Ethyl Mercaptan and Dimethyl Sulfide Isotopologues: A Route toward their Astrophysical Detection  

NASA Astrophysics Data System (ADS)

Using state-of-the-art computational methodologies, we predict a set of reliable rotational and torsional parameters for ethyl mercaptan and dimethyl sulfide monosubstituted isotopologues. This includes rotational, quartic, and sextic centrifugal-distortion constants, torsional levels, and torsional splittings. The accuracy of the present data was assessed from a comparison to the available experimental data. Generally, our computed parameters should help in the characterization and the identification of these organo-sulfur molecules in laboratory settings and in the interstellar medium.

Puzzarini, C.; Senent, M. L.; Domínguez-Gómez, R.; Carvajal, M.; Hochlaf, M.; Mogren Al-Mogren, M.

2014-11-01

348

Membrane reactor development for the kinetic resolution of ethyl 2-hydroxy-4-phenylbutyrate  

Microsoft Academic Search

(R)-Ethyl 2-hydroxy-4-phenylbutyrate is an important intermediate for the synthesis of several ACE-inhibitors (ACE = angiotensin-converting enzyme). A possible preparation of this intermediate is the kinetic resolution of the racemic 2-hydroxy compound. The enantioselective hydrolysis is catalyzed by the lipase from Pseudomonas cepacia in a two-phase system consisting of aqueous buffer and in organic solvent solubilized substrate. Production was carried out

A. Liese; U. Kragl; H. Kierkels; B. Schulze

2002-01-01

349

Enantioselective reductions of ethyl 2-oxo-4-phenylbutyrate by Saccharomyces cerevisiae dehydrogenases  

Microsoft Academic Search

A set of fusion proteins consisting of glutathione S-transferase linked to the N-terminus of putative dehydrogenases produced by baker’s yeast (Saccharomyces cerevisiae) was screened for the reduction of ethyl 2-oxo-4-phenylbutyrate in the presence of NADH and NADPH. Two dehydrogenases—Ypr1p and Gre2p—rapidly reduced this ?-ketoester, providing the (R)- and (S)-alcohol, respectively, with high stereoselectivities. The same enzymes were over-expressed in their

Iwona Kaluzna; Amy A. Andrew; Mariana Bonilla; Mark R. Martzen; Jon D. Stewart

2002-01-01

350

Studies on the Separation and Recovery of Thorium from Nitric Acid Medium using (2-ethyl hexyl) Phosphonic Acid, Mono (2-ethyl hexyl) Ester (PC88A)\\/N-Dodecane as Extractant System  

Microsoft Academic Search

This paper deals with the studies on the separation and recovery of thorium and 233-uranium from nitric acid medium using (2-ethyl hexyl) phosphonic acid, mono (2-ethyl hexyl) ester\\/n-dodecane as an extractant system. The different extraction parameters were investigated. The distribution ratio of thorium decreased with increase in nitric acid concentration. The optimum solvent concentration for quantitative separation of thorium from

A. K. Dinkar; Suman Kumar Singh; S. C. Tripathi; R. Verma; A. V. R. Reddy

2012-01-01

351

Studies on Separation and Recovery of Thorium From Nitric Acid Medium Using (2-ethyl Hexyl) Phosphonic Acid, Mono (2-ethyl Hexyl) Ester (PC88A) \\/ N- Dodecane as Extractant System  

Microsoft Academic Search

This paper deals with the studies on the separation and recovery of thorium and 233-uranium from nitric acid medium using (2-ethyl hexyl) phosphonic acid, mono (2-ethyl hexyl) ester\\/n-dodecane as an extractant system. The different extraction parameters were investigated. The distribution ratio of thorium decreased with increase in nitric acid concentration. The optimum solvent concentration for quantitative separation of thorium from

A. K. Dinkar; Suman Kumar Singh; S. C. Tripathi; R. Verma; A. V. R. Reddy

2012-01-01

352

Subchronic Toxicity Study in Rats of Two New Ethyl-Carbamates with Ixodicidal Activity  

PubMed Central

Female and male Wistar rats were used to determine the subchronic oral toxicities of two new ethyl-carbamates with ixodicidal activities (ethyl-4-bromphenyl-carbamate and ethyl-4-chlorphenyl-carbamate). The evaluated carbamates were administered in the drinking water (12.5, 25 and 50?mg/kg/day) for 90 days. Exposure to the evaluated carbamates did not cause mortality or clinical signs and did not affect food consumption or weight gain. However, exposure to these carbamates produced alterations in water consumption, hematocrit, percentages of reticulocytes, plasma proteins, some biochemical parameters (aspartate aminotransferase, gamma-glutamyl transpeptidase, cholinesterase, and creatinine activities), thiobarbituric acid reactive substances, and the relative weight of the spleen. Histologically, slight pathological alterations were found in the liver that were consistent with the observed biochemical alterations. The nonobserved adverse effect levels (NOAELs) of the evaluated carbamates were 12.5?mg/kg/day for both the female and male rats. The low severity and reversibility of the majority of the observed alterations suggest that the evaluated carbamates have low subchronic toxicity. PMID:24818142

Prado-Ochoa, Maria Guadalupe; Abrego-Reyes, Victor Hugo; Velazquez-Sanchez, Ana Maria; Munoz-Guzman, Marco Antonio; Ramirez-Noguera, Patricia; Angeles, Enrique; Alba-Hurtado, Fernando

2014-01-01

353

Chemodynamics of Methyl Parathion and Ethyl Parathion: Adsorption Models for Sustainable Agriculture  

PubMed Central

The toxicity of organophosphate insecticides for nontarget organism has been the subject of extensive research for sustainable agriculture. Pakistan has banned the use of methyl/ethyl parathions, but they are still illegally used. The present study is an attempt to estimate the residual concentration and to suggest remedial solution of adsorption by different types of soils collected and characterized for physicochemical parameters. Sorption of pesticides in soil or other porous media is an important process regulating pesticide transport and degradation. The percentage removal of methyl parathion and ethyl parathion was determined through UV-Visible spectrophotometer at 276?nm and 277?nm, respectively. The results indicate that agricultural soil as compared to barren soil is more efficient adsorbent for both insecticides, at optimum batch condition of pH 7. The equilibrium between adsorbate and adsorbent was attained in 12 hours. Methyl parathion is removed more efficiently (by seven orders of magnitude) than ethyl parathion. It may be attributed to more available binding sites and less steric hindrance of methyl parathion. Adsorption kinetics indicates that a good correlation exists between distribution coefficient (Kd) and soil organic carbon. A general increase in Kd is noted with increase in induced concentration due to the formation of bound or aged residue. PMID:24689059

Rafique, Uzaira; Balkhair, Khaled S.; Ashraf, Muhammad Aqeel

2014-01-01

354

In vitro evaluation of transdermal patches of flurbiprofen with ethyl cellulose.  

PubMed

This study was aimed to determine effects of penetration enhancers and plasticizers on drug release from rationally designed formulations of flurbiprofen based transdermal drug delivery system. Matrix type transdermal patches were formulated with ethyl cellulose (EC) as a polymer by using plate casting method. The plasticizers such as propylene glycol (PG) and dibutyl phthalate (DBP), and enhancers such as Span 20, Tween 20, sodium lauryl sulfate (SLS), isopropyl myristate (IPM) and ethanol (EtOH) were formulated in different concentrations in the patches. Such different combinations of polymer with various enhancers and plasticizers in patches were evaluated for their effect on the physicochemical properties and drug release behavior of flurbiprofen. The drug release study was carried out by the paddle-over-disk method and permeation of drug was performed by Franz diffusion cell using rabbit skin. Patches having ethanol with ethyl cellulose showed more uniformity in the physical properties while the smoothness and clarity of patches containing sodium lauryl sulfate were not satisfactory. The drug release from patches followed Higuchi and Korsmeyer-Pappas model while maximum drug release was obtained by isopropyl myristate (903 microg). It was concluded that the patches having ethyl cellulose with isopropyl myristate and propylene glycol are more useful for transdermal patches of flurbiprofen. PMID:25272649

Idrees, Arfat; Rahman, Nisar Ur; Javaid, Zeeshan; Kashif, Muhammad; Aslam, Irfan; Abbas, Khizar; Hussain, Talib

2014-01-01

355

A solventless route to 1-ethyl-3-methylimidazolium fluoride hydrofluoride, [C2mim][F] x xHF.  

PubMed

The ionic liquid 1-ethyl-3-methylimidazolium fluoride hydrofluoride, [C2mim][F] x xHF, has been synthesized through a new, solventless route that excludes halogen metathesis. The byproducts are salts, alcohols, and carbon dioxide. PMID:18549285

Rijksen, Christiaan; Rogers, Robin D

2008-07-18

356

A rapid method for analysis of tert-butyl hydroquinone (TBHQ) in ethyl esters of fish oil  

Microsoft Academic Search

A rapid, quantitative gas Chromatographic method is described for quantitating the phenolic antioxidant,tert- butyl hydroquinone (TBHQ), in fish oil ethyl esters. The procedure entails silyl derivatization of TBHQ in an acetonitrile\\u000a solution of ethyl esters followed by capillary gas chromatography (GC) analysis with an internal standard method of quantitation.\\u000a Average recoveries of spiked samples were 98% at the legal limit

Teresa P. Icenhour; Frances M. Van Dolah

1991-01-01

357

Miscibility of ethyl cellulose\\/copolyamide6\\/66\\/1010 blends by viscometry and refractive index method  

Microsoft Academic Search

The miscibility of ethyl cellulose (EC)\\/copolyamide6\\/66\\/1010 (PA-130) in formic acid is studied by viscometry and refractive\\u000a index techniques at 25°C. Using viscosity data, the criteria ?b, ?b?, ?[?]m, interaction parameter ?, ? and thermodynamic parameter ? are calculated. These investigations indicate that blend of EC\\/PA-130\\u000a is miscible when the ethyl cellulose content is more than 50 wt % in the

Xiuzhen Zhang; Yuhua Shen; Anjian Xie; Sulian Gao; Zhiying Xing

2011-01-01

358

Low-Temperature Complete Oxidation of Ethyl Acetate Over CeO 2 -Supported Precious Metal Catalysts  

Microsoft Academic Search

Catalytic combustion of ethyl acetate was investigated over various CeO2-supported precious metal catalysts prepared by impregnation method, and the effect of reduction treatment on the activity\\u000a was examined. Among the catalysts tested, Ru\\/CeO2 achieved the highest activity for ethyl acetate combustion, and the activity was almost unchanged by the heat treatment in\\u000a a hydrogen atmosphere. In the cases of Pt\\/CeO2,

Tomohiro Mitsui; Toshiaki Matsui; Ryuji Kikuchi; Koichi Eguchi

2009-01-01

359

Absolute quantification of UGT1A1 in various tissues and cell lines using isotope label-free UPLC-MS/MS method determines its turnover number and correlates with its glucuronidation activities.  

PubMed

Uridine 5'-diphosphate-glucuronosyltransferase (UGT)1A1 is a major phase II metabolism enzyme responsible for glucuronidation of drugs and endogenous compounds. The purpose of this study was to determine the expression level of UGT1A1 in human liver microsomes and human cell lines by using an isotope label-free LC-MS/MS method. A Waters Ultra performance liquid chromatography (UPLC) system coupled with an API 5500Qtrap mass spectrometer was used for the analysis. Two signature peptides (Pep-1, and Pep-2) were employed to quantify UGT1A1 by multiple reaction monitoring (MRM) approach. Standard addition method was used to validate the assay to account for the matrix effect. 17?-Estradiol was used as the marker substrate to determine UGT1A1 activities. The validated method has a linear range of 200-0.0195nM for both signature peptides. The precision, accuracy, and matrix effect were in acceptable ranges. UGT1A1 expression levels were then determined using 8 individual human liver microsomes, a pooled human liver microsomes, three UGT1A1 genotyped human liver microsomes, and four cell lines (Caco-2, MCF-7, Hela, and HepG2). The correlations study showed that the UGT1A1 protein levels were strongly correlated with its glucuronidation activities in human liver microsomes (R(2)=0.85) and in microsomes prepared from cell lines (R(2)=0.95). Isotope-labeled peptides were not necessary for LC-MS/MS quantitation of proteins. The isotope label-free absolute quantification method used here had good accuracy, sensitivity, linear range, and reproducibility, and were used successfully for the accurate determination of UGT1A1 from tissues and cell lines. PMID:24055854

Xu, Beibei; Gao, Song; Wu, Baojian; Yin, Taijun; Hu, Ming

2014-01-01

360

Effects of ethanol and long-chain ethyl ester concentrations on volatile partitioning in a whisky model system.  

PubMed

Ethanolic atmospheric pressure chemical ionization mass spectrometry (APCI-MS) was used to analyze the headspace concentrations of a test set of 14 whisky volatile compounds above a series of aqueous ethanolic solutions differing in alcohol content (5-40% ABV) and with regard to concentration of ethyl hexadecanoate (0-500 mg/L). The latter was selected to represent the long-chain ethyl esters found at various concentrations in new-make spirit. Headspace ion intensities were modeled against ethanol and ethyl hexadecanoate concentrations as factors. A separate model was prepared for each compound. Not surprisingly, ethanol content in the range of 5-40% ABV had a significant effect (P < 0.0001) on headspace volatile concentrations of all volatile compounds, whereas the ethyl hexadecanoate concentration had a selective effect of reducing headspace concentrations of the more hydrophobic compounds (log P > 2.5). This finding is discussed in terms of the "structuring" effects of ethyl hexadecanoate when present above critical micelle concentration, leading to the selective incorporation of hydrophobic volatile compounds into the interior of micelle-like structures. Data presented illustrate that dilution of whiskies to 23% ABV for "nosing" in the presence of long-chain ethyl esters is likely to change the balance of volatile compounds in the headspace and thus the perceived aroma character. PMID:22958228

Boothroyd, Emily L; Linforth, Robert S T; Cook, David J

2012-10-10

361

Effects of repeated applications of chlorimuron-ethyl on the soil microbial biomass, activity and microbial community in the greenhouse.  

PubMed

The impacts of repeated chlorimuron-ethyl applications on soil microbial community structure and function were studied under greenhouse conditions. Chlorimuron-ethyl was applied to soil samples at three different doses [1-,10-,100-fold of recommended field rate (T1, T10, T100)] for 3 years. The half-lives of chlorimuron-ethyl were 37.1-54.6 days. The soil microbial biomass (microbial biomass carbon and total phospholipid fatty acid), the microbial activity (basal respiration and average well color development), the ratio of Gram-negative/Gram-positive bacteria and Shannon index were stimulated by chlorimuron-ethyl during the initial period. Except for T100, the other treatments recovered to the untreated level. The ratio of fungi/bacteria decreased during the initial period and then recovered in the end. Principal component analysis of phospholipid fatty acid showed that chlorimuron-ethyl altered the microbial community structure. Except got T100, T1 and T10 were not different from the control at the end of experiment. These results suggested a dosage effect of chlorimuron-ethyl on the living microbial biomass and the microbial community. PMID:24264144

Xu, Jun; Zhang, Ying; Dong, Fengshou; Liu, Xingang; Wu, Xiaohu; Zheng, Yongquan

2014-02-01

362

Lefetamine-derived designer drugs N-ethyl-1,2-diphenylethylamine (NEDPA) and N-iso-propyl-1,2-diphenylethylamine (NPDPA): metabolism and detectability in rat urine using GC-MS, LC-MSn and LC-HR-MS/MS.  

PubMed

N-Ethyl-1,2-diphenylethylamine (NEDPA) and N-iso-propyl-1,2-diphenylethylamine (NPDPA) are two designer drugs, which were confiscated in Germany in 2008. Lefetamine (N,N-dimethyl-1,2-diphenylethylamine, also named L-SPA), the pharmaceutical lead of these designer drugs, is a controlled substance in many countries. The aim of the present work was to study the phase I and phase II metabolism of these drugs in rats and to check for their detectability in urine using the authors' standard urine screening approaches (SUSA). For the elucidation of the metabolism, rat urine samples were worked up with and without enzymatic cleavage, separated and analyzed by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-high resolution-tandem mass spectrometry (LC-HR-MS/MS). According to the identified metabolites, the following metabolic pathways for NEDPA and NPDPA could be proposed: N-dealkylation, mono- and bis-hydroxylation of the benzyl ring followed by methylation of one of the two hydroxy groups, combinations of these steps, hydroxylation of the phenyl ring after N-dealkylation, glucuronidation and sulfation of all hydroxylated metabolites. Application of a 0.3 mg/kg BW dose of NEDPA or NPDPA, corresponding to a common lefetamine single dose, could be monitored in rat urine using the authors' GC-MS and LC-MS(n) SUSA. However, only the metabolites could be detected, namely N-deethyl-NEDPA, N-deethyl-hydroxy-NEDPA, hydroxy-NEDPA, and hydroxy-methoxy-NEDPA or N-de-iso-propyl-NPDPA, N-de-iso-propyl-hydroxy-NPDPA, and hydroxy-NPDPA. Assuming similar kinetics, an intake of these drugs should also be detectable in human urine. PMID:24591097

Wink, Carina S D; Meyer, Golo M J; Wissenbach, Dirk K; Jacobsen-Bauer, Andrea; Meyer, Markus R; Maurer, Hans H

2014-10-01

363

G2 ab initio calculations of the enthalpy of formation of hydrazoic acid, methyl azide, ethyl azide, methyl amine, and ethyl amine  

NASA Astrophysics Data System (ADS)

G2 calculations on the title compounds yield total energies, E0=-164.560 33, -203.776 24, -243.004 79, -95.666 91, and -134.894 58 hartrees and ?Hf298=70.4, 71.0, 64.5, -5.9, and -12.4 kcal mol-1, respectively. Agreement with literature values for hydrazoic acid and both amines is good. We discuss the calculation for methyl and ethyl azide in relation to our recent experimental results from hydrogen calorimetry of a group of higher organic azides. While a substantial improvement over the existing literature value, the calculation yields an estimate for ?Hhyd298=-76.9 kcal mol-1, that is, 2.2 kcal mol-1 less exothermic than the lower limit of our estimated experimental uncertainty.

Rogers, Donald W.; McLafferty, Frank J.

1995-11-01

364

LC-MS-MS analysis of dietary supplements for N-ethyl-?-ethyl-phenethylamine (ETH), N, N-diethylphenethylamine and phenethylamine.  

PubMed

There has been a recent rise in the number of cases of athletes being banned from competition because of positive tests for prohibited substances in their biological specimens. Most of these substances are on the World Anti-Doping Agency (WADA) prohibited list, while others are not specifically named on the list. N-Ethyl-?-ethyl-phenethylamine (ETH), a derivative of phenethylamine (PEA), is one of these unlisted substances and shares chemical and biological effects to the amphetamines, which are listed on the WADA prohibited substances list. It is classified as Category 6B stimulant on the list. This study was directed toward the development of an liquid chromatography tandem mass spectrometry (LC-MS-MS) method for the analysis of ETH in performance-enhancing dietary supplement. A standard was prepared and confirmed by spectroscopic analysis, which was then used to develop the analytical procedure. The procedure was validated and found to have an limit of detection of 2.5 ng/mL, limit of quantification of 5 ng/mL and upper limit of linearity of 500 ng/mL, with within-day variability at the 10-ng/mL level range of 3.88-7.89% (n = 6) and 1.39-3.36% (n = 6) for the 100-ng/mL level. The day-to-day variability was 9.8% for the low control and 3.1% for the high control. The method was used to analyze a variety of dietary supplements for ETH as well as PEA and its N, N-diethyl derivative (NDP). PMID:24344073

ElSohly, Mahmoud A; Gul, Waseem

2014-03-01

365

Prompt-NO formation in methane/oxygen/nitrogen flames seeded with oxygenated volatile organic compounds: Methyl ethyl ketone or ethyl acetate  

SciTech Connect

In the present work, CH and NO profiles are determined using laser-induced fluorescence (LIF) measurements in eight low-pressure laminar flames of CH{sub 4}/O{sub 2}/N{sub 2} containing various amounts of methyl ethyl ketone or ethyl acetate with respect to the equivalence ratio. Relative CH LIF signals are calibrated using cavity ring-down spectroscopy (CRDS), while NO LIF calibration is performed in the burned gases of NO seeded flames. Temperature measurements are obtained using a coated Pt/Rh thermocouple and serve as temperature profiles input for Chemkin modeling. Volatile organic compound (VOC) submechanisms, previously validated upon major and intermediate species profiles measured using sampling techniques, are incorporated into the GDF-Kin 3.0{sub N}CN for the CH{sub 4} oxidation. This mechanism is adjusted and validated to predict the effect of VOCs seeding on CH and NO formation. It takes into account not only the CH and NO profiles but those previously measured. When methane is replaced by either MEK or EA, the NO mole fraction in the burned gases and the CH peak value are found to jointly decrease, indicating that NO is mainly formed according to the prompt-NO mechanism. According to the kinetic analysis, the VOC impact on NO formation is demonstrated. It is shown that CH radical formation, through the C1 sequence, mainly involves the CH{sub 3} radical, which is formed with the same propensity by one molecule of methane, MEK, or EA. Due to the methane replacement by VOC while the equivalence ratio is maintained constant, we found that the CH peak value decrease follows the total fuel volumetric flow rate decrease, yielding, an NO decrease in the burned gases. (author)

Lamoureux, N.; El-Bakali, A.; Gasnot, L.; Pauwels, J.F.; Desgroux, P. [UMR CNRS 8522 PC2A ''Physicochimie des Processus de Combustion et de l'Atmosphere,'' Universite des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq Cedex (France)

2008-04-15

366

Glycoconjugates in the detection of alcohol abuse.  

PubMed

Up to 30% of all hospital admissions and health-care costs may be attributable to alcohol abuse. Ethanol, its oxidative metabolites, acetaldehyde and ROS (reactive oxygen species), non-oxidative metabolites of alcohol [e.g. FAEEs (fatty acid ethyl esters)] and the ethanol-water competition mechanism are all involved in the deregulation of glycoconjugate (glycoprotein, glycolipid and proteoglycan) metabolic processes including biosynthesis, modification, transport, secretion, elimination and catabolism. An increasing number of new alcohol biomarkers that are the result of alcohol-induced glycoconjugate metabolic errors have appeared in the literature. Glycoconjugate-related alcohol markers are involved in, or are a product of, altered glycoconjugate metabolism, e.g. CDT (carbohydrate-deficient transferrin), SA (sialic acid), plasma SIJ (SA index of apolipoprotein J), CETP (cholesteryl ester transfer protein), ?-HEX (?-hexosaminidase), dolichol, EtG (ethyl glucuronide) etc. Laboratory tests based on changes in glycoconjugate metabolism are useful in settings where the co-operativeness of the patient is impaired (e.g. driving while intoxicated) or when a history of alcohol use is not available (e.g. after trauma). In clinical practice, glycoconjugate markers of alcohol use/abuse let us distinguish alcoholic from non-alcoholic tissue damage, having important implications for the treatment and management of diseases. PMID:21265805

Waszkiewicz, Napoleon; Szajda, S?awomir Dariusz; K?pka, Alina; Szulc, Agata; Zwierz, Krzysztof

2011-01-01

367

Icosapent Ethyl  

MedlinePLUS

... Toprol XL), nadolol (Corgard), and propranolol (Inderal); diuretics ('water pills'); estrogen-containing contraceptives (birth control pills, patches, rings, and injections); or estrogen replacement therapy. Your doctor may need ...

368

Protective Effect of Ethyl Acetate Fraction of Stereospermum Suaveolens Against Hepatic Oxidative Stress in STZ Diabetic Rats  

PubMed Central

Stereospermum suaveolens is a folk remedy for the treatment of diabetes and liver disorders in southern parts of India. In the present study, the protective effect of the ethyl acetate fraction of ethanol extract from S. suaveolens against hepatic oxidative stress was evaluated in streptozotocin (STZ)-induced diabetic rats for 14 days. The ethyl acetate fraction was administered orally to the STZ diabetic rats at the doses of 200 and 400 mg/kg. Blood glucose level was measured according to glucose oxidase method. In order to determine hepatoprotective activity, changes in the levels of serum biomarker enzymes such as aspartate transaminase (AST), alanine transaminase (ALT), and serum alkaline phosphatase (SALP) were assessed in the ethyl acetate fraction treated diabetic rats and were compared with the levels in diabetic control rats. In addition, the antioxidant activity of ethyl acetate fraction was evaluated using various hepatic parameters such as thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT). It was found that administration of ethyl acetate fraction (200 and 400 mg/kg) produced a significant (P < 0.001) fall in fasting blood glucose level, TBARS, bilirubin, AST, ALT, and SALP, while elevating the GSH levels, and SOD and CAT activities in diabetic rats. Histopathologic studies also revealed the protective effect of ethyl acetate fraction on the liver tissues of diabetic rats. It was concluded from this study that the ethyl acetate fraction from ethanol extract of S. suaveolens modulates the activity of enzymatic and nonenzymatic antioxidants and enhances the defense against hepatic oxidative stress in STZ-induced diabetic rats. PMID:24716175

Balasubramanian, Thirumalaiswamy; Senthilkumar, G. P; Karthikeyan, M.; Chatterjee, Tapan Kumar

2013-01-01

369

Patterning and hardening of gold black infrared absorber by shadow mask deposition with ethyl cyanoacrylate  

NASA Astrophysics Data System (ADS)

Patterning of gold-black infrared absorbing films by stencil lithography and hardening by polymer infusion is reported. Gold black nano-structured films are deposited through a thin metal shadow mask in a thermal evaporator in ~400 mTorr pressure of inert gas, followed by ethyl cyanoacrylate fuming through the same mask to produce rugged IR absorptive patterns of ~100 micron scale dimensions. Infrared absorptivity is determined by transmission and reflectivity measurements using a Fourier spectrometer and infrared microscope. Results indicate that the optimized hardening process reduces the usual degradation of the absorptivity with age. This work has potential application to infrared array bolometers.

Panjwani, Deep; Nader-Esfahani, Nima; Maukonen, Doug; Rezadad, Imen; Boroumand, Javaneh; Smith, Evan; Nath, Janardan; Peale, R. E.

2013-06-01

370

Chemical and enzymatic approaches to the synthesis of optically pure ethyl (R)-4-cyano-3-hydroxybutanoate.  

PubMed

Ethyl (R)-4-cyano-3-hydroxybutanoate (HN) is an important chiral synthon for side chain of the cholesterol-lowering drug atorvastatin (Lipitor), which is the hydroxymethylglutaryl CoA reductase inhibitor. HN is also used as a synthon in the production of L-carnitine and (R)-4-amino-3-hydroxybutanoic acid. It is necessary to have a clear understanding of the synthesis process of HN for its extensive use. This review gives an overview of different synthetic strategies of optically active HN, including chemical and enzymatic approaches. The emphasis is focused mainly on the synthetic routes using biocatalysts, such as halohydrin dehalogenase, nitrilase, carbonyl reductase, and lipase. PMID:24232833

You, Zhong-Yu; Liu, Zhi-Qiang; Zheng, Yu-Guo

2014-01-01

371

Analysis of ethyl and methyl centralite vibrational spectra for mapping organic gunshot residues.  

PubMed

Detection of ethyl and methyl centralites in gunshot residues is important in forensic science due to their limited contamination from environmental sources compared to other organic residues. However, the vibrational frequencies of centralites are little explored and their frequency assignments are incomplete. Herein, we investigated vibrational frequencies of centralites based on Density functional theory (DFT) to understand their vibrations. The simulated frequencies exhibit excellent agreement with the experimental data, and the detailed assignments are comprehensively elaborated. We also demonstrate that centralite particles could be detected through Raman imaging based on their fingerprints. This work is very important for the further vibrational studies in detecting and tracing centralites in gunshot residues. PMID:25005050

Zeng, Jianbo; Qi, Ji; Bai, Fuquan; Yu, Jorn Chi Chung; Shih, Wei-Chuan

2014-09-01

372

Solvent and pressure influences on air separation of liquid crystalline triheptyl cellulose composite ethyl cellulose membranes  

SciTech Connect

Air separation of a cholesteric liquid crystalline triheptyl cellulose/ethyl cellulose (3/97) binary composite membrane prepared from tetrahydrofuran, chloroform, and dichloromethane solutions was studied at different pressure differences across the membrane by the variable volume method. With an increasing pressure difference in the range from 0.06 to 0.42 MPa, the flux and the oxygen concentration of the oxygen-enriched air through the membrane both increase. The air separation capability depends on the boiling point of the membrane-forming solvent and the membrane thickness. 15 refs., 4 figs., 1 tab.

Li, X.G.; Huang, M.R.; Lin, G.; Yang, P.C. (Tianjin Inst. of Textile Science and Technology (China))

1994-03-01

373

Grafting of Methacrylonitrile and Ethyl Methacrylate onto Jute Fibre: Physico-chemical Characteristics of Grafted Jute  

NASA Astrophysics Data System (ADS)

Modification of bleached jute fibre was done by graft co-polymerization with vinyl monomers e.g. methacrylonitrile and ethyl methacrylate, in aqueous medium using H2O2-Na2S2O3 as redox initiators. To make the process efficient, the optimized polymerization condition was established. The maximum percent grafting and grafting efficiency obtained at optimum grafting condition were 11.3 and 20.4% for MAN, respectively and that of 17.6 and 27.5% for EMA. Modification of bleached jute fibre with MAN and EMA reduced the loss in breaking strength and the yellowing on exposure to sunlight in air.

Mondal, Md. Ibrahim H.; Islam Farouqui, Faisul; Abu Hanif, Md.; Shafiur Rahman, G. M.; Asadul Hoque, Md.

2005-10-01

374

Communication: Substrate induced dehydrogenation: Transformation of octa-ethyl-porphyrin into tetra-benzo-porphyrin  

NASA Astrophysics Data System (ADS)

Individual molecules of octa-ethyl-porhphyrin-iron(III)-chloride adsorbed on a Cu(111) surface are studied by scanning tunneling microscopy. Upon moderate heating the molecules are found to transform into Fe-tetra-benzo-porphyrin at a surprisingly low temperature of 380 K. If the annealing is interrupted, the different steps of the transformation can be imaged. By evaluating the ratio of transformed molecules as function of annealing temperature, an approximate activation energy of 1.2 eV ± 0.1 eV could be determined.

van Vörden, D.; Lange, M.; Schmuck, M.; Schaffert, J.; Cottin, M. C.; Bobisch, C. A.; Möller, R.

2013-06-01

375

4-Hy-droxy-3-meth-oxy-benzaldehyde 4-ethyl-thio-semicarbazone.  

PubMed

In the crystal structure of the title compound, C11H15N3O2S, the C-N-N-C and C-N-C-C torsion angles involving the benzene ring and ethyl group are 11.91?(15) and 99.4?(2)°, respectively. An intra-molecular N-H?N hydrogen bond is observed. In the crystal, mol-ecules are linked via N-H?O and N-H?S hydrogen bonds into a three-dimensional hydrogen bonded network. Finally, the molecules show a herringbone arrangement when viewed along the a axis. PMID:25249915

de Oliveira, Adriano Bof; Beck, Johannes; Daniels, Jörg; Feitosa, Bárbara Regina Santos

2014-08-01

376

Simulating the vibrational spectra of ionic liquid systems: 1-ethyl-3-methylimidazolium acetate and its mixtures.  

PubMed

The vibrational spectra of the ionic liquid 1-ethyl-3-methylimidazolium acetate and its mixtures with water and carbon dioxide are calculated using ab initio molecular dynamics simulations, and the results are compared to experimental data. The new implementation of a normal coordinate analysis in the trajectory analyzer TRAVIS is used to assign the experimentally observed bands to specific molecular vibrations. The applied computational approaches prove to be particularly suitable for the modeling of bulk phase effects on vibrational spectra, which are highly important for the discussion of the microscopic structure in systems with a strong dynamic network of intermolecular interactions, such as ionic liquids. PMID:25028030

Thomas, Martin; Brehm, Martin; Hollóczki, Oldamur; Kelemen, Zsolt; Nyulászi, László; Pasinszki, Tibor; Kirchner, Barbara

2014-07-14

377

Simulating the vibrational spectra of ionic liquid systems: 1-Ethyl-3-methylimidazolium acetate and its mixtures  

NASA Astrophysics Data System (ADS)

The vibrational spectra of the ionic liquid 1-ethyl-3-methylimidazolium acetate and its mixtures with water and carbon dioxide are calculated using ab initio molecular dynamics simulations, and the results are compared to experimental data. The new implementation of a normal coordinate analysis in the trajectory analyzer TRAVIS is used to assign the experimentally observed bands to specific molecular vibrations. The applied computational approaches prove to be particularly suitable for the modeling of bulk phase effects on vibrational spectra, which are highly important for the discussion of the microscopic structure in systems with a strong dynamic network of intermolecular interactions, such as ionic liquids.

Thomas, Martin; Brehm, Martin; Hollóczki, Oldamur; Kelemen, Zsolt; Nyulászi, László; Pasinszki, Tibor; Kirchner, Barbara

2014-07-01

378

Tris(1-ethyl-3-methyl-imidazolium) hexa-bromidoeuropate(III)  

PubMed Central

The crystal structure of the title compound, (C6H11N2)3[EuBr6], consists of 1-ethyl-3-methyl­imidazolium cations and centrosymmetric octa­hedral hexa­bromido­europate anions. The [EuBr6]3? anions are located at the corners and face-centres of the monoclinic unit cell. Characteristic hydrogen-bonding inter­actions can be observed between the bromide anions and the acidic H atoms of the imidazolium cations. PMID:21202797

Pellens, Michael; Thijs, Ben; Van Hecke, Kristof; Van Meervelt, Luc; Binnemans, Koen; Nockemann, Peter

2008-01-01

379

Effects of pH on Chemical Stability and Deesterification of Fenoxaprop-ethyl by Purified Enzymes, Bacterial Extracts, and Soils  

Microsoft Academic Search

De-esterification is an initial step in the metabolism of certain herbicides, for example, fenoxaprop- ethyl ((()-ethyl 2-(4-((6-chloro-2-benzoxaolyl)oxy)phenoxy)propanoate) (FE). The ethyl-ester bond cleavage of FE to fenoxaprop acid (FA) by purified enzymes, crude bacterial enzyme preparations, and soils was investigated. In similar experiments fluorescein diacetate (FDA) was used as an alternative substrate. FE stability was pH sensitive in acidic buffered solutions;

Robert M. Zablotowicz; Robert E. Hoagland; William J. Staddon; Martin A. Locke

2000-01-01

380

Effects of etizolam and ethyl loflazepate on the P300 event-related potential in healthy subjects  

PubMed Central

Background Benzodiazepines carry the risk of inducing cognitive impairments, which may go unnoticed while profoundly disturbing social activity. Furthermore, these impairments are partly associated with the elimination half-life (EH) of the substance from the body. The object of the present study was to examine the effects of etizolam and ethyl loflazepate, with EHs of 6 h and 122 h, respectively, on information processing in healthy subjects. Methods Healthy people were administered etizolam and ethyl loflazepate acutely and subchronically (14 days). The auditory P300 event-related potential and the neuropsychological batteries described below were employed to assess the effects of drugs on cognition. The P300 event-related potential was recorded before and after drug treatments. The digit symbol test, trail making test, digit span test and verbal paired associates test were administered to examine mental slowing and memory functioning. Results Acute administration of drugs caused prolongation in P300 latency and reduction in P300 amplitude. Etizolam caused a statistically significant prolongation in P300 latency compared to ethyl loflazepate. Furthermore, subchronic administration of etizolam, but not ethyl loflazepate, still caused a weak prolongation in P300 latency. In contrast, neuropsychological tests showed no difference. Conclusions The results indicate that acute administration of ethyl loflazepate induces less effect on P300 latency than etizolam. PMID:21047414

2010-01-01

381

Antifungal and antioxidant activity of Crassocephalum bauchiense (Hutch.) Milne-Redh ethyl acetate extract and fractions (Asteraceae)  

PubMed Central

Background Crassocephalum bauchiense is a flowering plant, found in the West Region of Cameroon. Previous studied has highlighted the antibacterial and the dermal toxicological safety as well as the immunomodulatory activities of the ethyl acetate extract of its dry leaves. As an extension of the previous researches, the current work has been undertaken to evaluate the in vitro antifungal and antioxidant activities of C. bauchiense dried leaves ethyl acetate extract and fractions. Methods The extract was obtained by maceration in ethyl acetate and further fractionated into six fractions labeled F1 to F6 by flash chromatography. The antifungal activity of the extract and fractions against yeasts and dermatophytes was evaluated using broth microdilution method. Antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO) and ?-carotene - linoleic acid assays. Results The extract (MIC = 0.125 - 4 mg/ml) was found to be more active on dermatophytes and yeasts compared to the fractions. The ethyl acetate extract and fractions exhibited strong scavenging activity on DPPH (CI50 = 28.57 - 389.38 ?g/ml). The fractions F3 and F6 expressed best antioxidant activity on DPPH radicals compared to the crude extract. Conclusion The results of these findings clearly showed that C. bauchiense ethyl acetate extract has a significant antifungal and antioxidant activity. It is therefore a source of active compounds that might be used as antifungal and antioxidant agents. PMID:24742210

2014-01-01

382

Tropane ethyl esters in illicit cocaine: isolation, detection, and determination of new manufacturing by-products from the clandestine purification of crude cocaine base with ethanol.  

PubMed

Seven ethyl homologues of known tropane esters have recently been detected as impurities in the gas chromatographic signature profiles of authentic Peruvian illicit cocaine base and hydrochloride exhibits. Peruvian cocaine base processors are now known to use ethanol for the purification of crude cocaine base. This process is referred to as the "base lavada" or "washed base" process and is a recent substitute method for the potassium permanganate oxidation purification methodology. Seven ethyl ester homologues were formed in illicit cocaine from the transesterification of known tropane methyl esters or possibly ethyl esterification of their respective tropane C-2 carboxylic acids in the presence of ethanol. Exhibits containing these compounds were subjected to gas chromatographic-mass spectrometric analyses to determine their identity and were subsequently synthesized to verify their structures. Quantitative determinations were obtained from ion-pair chromatography isolation followed by gas chromatography with flame ionization detection. Specifically, hexanoylecgonine ethyl ester, cocaethylene, cis-cinnamoylecgonine ethyl ester, trans-cinnamoylecgonine ethyl ester, 3',4',5'-trimethoxybenzoylecgonine ethyl ester, cis-3',4',5'-trimethoxycinnamoylecgonine ethyl ester, and trans-3',4',5'-trimethoxycinnamoylecgonine ethyl ester were detected and characterized. When present, these compounds were detected at levels ranging from 8.6 x 10(-4) to 9.3 x 10(-1)% relative to cocaine. PMID:18471211

Casale, John F; Boudreau, Danielle K; Jones, Laura M

2008-05-01

383

Synthesis and antibacterial activity of 3-substituted-6-(3-ethyl-4-methylanilino)uracils.  

PubMed

Numerous 3-substituted-6-(3-ethyl-4-methylanilino)uracils (EMAU) have been synthesized and screened for their capacity to inhibit the replication-specific bacterial DNA polymerase IIIC (pol IIIC) and the growth of Gram+ bacteria in culture. Direct alkylation of 2-methoxy-6-amino-4-pyrimidone produced the N3-substituted derivatives, which were separated from the byproduct 4-alkoxy analogues. The N3-substituted derivatives were heated with a mixture of 3-ethyl-4-methylaniline and its hydrochloride to effect displacement of the 6-amino group and simultaneous demethylation of the 2-methoxy group to yield target compounds in good yields. Certain intermediates, e.g. the 3-(iodoalkyl) compounds, were converted to a variety of (3-substituted-alkyl)-EMAUs by displacement. Most compounds were potent competitive inhibitors of pol IIIC (K(i)s 0.02-0.5 microM), and those with neutral, moderately polar 3-substituents had potent antibacterial activity against Gram+ organisms in culture (MICs 0.125-10 microg/mL). Several compounds protected mice from lethal intraperitoneal (ip) infections with S. aureus (Smith) when given by the ip route. A water soluble derivative, 3-(4-morpholinylbutyl)-EMAU hydrochloride, given subcutaneously, prolonged the life of infected mice in a dose dependent manner. PMID:16250666

Zhi, Chengxin; Long, Zheng-yu; Manikowski, Andrzej; Brown, Neal C; Tarantino, Paul M; Holm, Karsten; Dix, Edward J; Wright, George E; Foster, Kim A; Butler, Michelle M; LaMarr, William A; Skow, Donna J; Motorina, Irina; Lamothe, Serge; Storer, Richard

2005-11-01

384

Effects of wildlife of ethyl and methyl parathion applied to California USA rice fields  

USGS Publications Warehouse

Selected rice fields on the Sacramento National Wildlife Refuge Complex were aerially sprayed one time during May or June 1982 with either ethyl (0.11 kg Al/ha) or methyl (0.84 kg AI/ha) parathion for control of tadpole shrimp, Triops longicaudatus. No sick or dead vertebrate wildlife were found or adjacent to the treated rice fields after spraying. Specimens of the following birds and mammals were assayed for brain cholinesterase (ChE) activity to determine exposure to either form of parathion; house mouse, Mus musculus; black-tailed jackrabbit, Lepus californicus; mallard, Anas platyrhynchos; ring-necked pheasant, Phasianus colchicus; American coot, Fulica americana; and red-winged blackbird, Agelaius phoeniceus. Both mice and pheasants from methyl parathion-treated fields had overall mean ChE activities that were significantly (P < 0.05) inhibited compared with controls, and 7, 40, 54 and 57% of individual blackbirds, pheasant, mice, and coots, respectively, had inhibited brain ChE activities (i.e., less than -2 SD of control mean). Although no overall species effect was detected for ethyl parathoid treatment, pheasants (43%), coots (33%), and mice (37%) had significantly inhibited brain ChE activities. Neither of the parathion treatment appeared acutely hazardous to wildlife in or adjacent to rice fields, but sufficient information on potential hazards was obtained to warrant caution in use of these chemicals, especially methyl parathion, in rice fields.

Custer, T.W.; Hill, E.F.; Ohlendorf, H.M.

1985-01-01

385

Effects on wildlife of ethyl and methyl parathion applied to California rice fields  

USGS Publications Warehouse

Selected rice fields on the Sacramento National Wildlife Refuge Complex were aerially sprayed one time during May or June 1982 with either ethyl (0.11 kg Al/ha) or methyl (0.84 kg AI/ha) parathion for control of tadpole shrimp, Triops longicaudatus. No sick or dead vertebrate wildlife were found or adjacent to the treated rice fields after spraying. Specimens of the following birds and mammals were assayed for brain cholinesterase (ChE) activity to determine exposure to either form of parathion; house mouse, Mus musculus; black-tailed jackrabbit, Lepus californicus; mallard, Anas platyrhynchos; ring-necked pheasant, Phasianus colchicus; American coot, Fulica americana; and red-winged blackbird, Agelaius phoeniceus. Both mice and pheasants from methyl parathion-treated fields had overall mean ChE activities that were significantly (P < 0.05) inhibited compared with controls, and 7, 40, 54 and 57% of individual blackbirds, pheasant, mice, and coots, respectively, had inhibited brain ChE activities (i.e., less than -2 SD of control mean). Although no overall species effect was detected for ethyl parathoid treatment, pheasants (43%), coots (33%), and mice (37%) had significantly inhibited brain ChE activities. Neither of the parathion treatment appeared acutely hazardous to wildlife in or adjacent to rice fields, but sufficient information on potential hazards was obtained to warrant caution in use of these chemicals, especially methyl parathion, in rice fields.

Custer, T.W.; Hill, E.F.; Ohlendorf, H.M.

1985-01-01

386

Ethyl Acetate Extract of Artemisia anomala S. Moore Displays Potent Anti-Inflammatory Effect  

PubMed Central

Artemisia anomala S. Moore has been widely used in China to treat inflammatory diseases for hundreds of years. However, mechanisms associated with its anti-inflammatory effect are not clear. In this study, we prepared ethyl acetate, petroleum ether, n-BuOH, and aqueous extracts from ethanol extract of Artemisia anomala S. Moore. Comparing anti-inflammatory effects of these extracts, we found that ethyl acetate extract of this herb (EAFA) exhibited the strongest inhibitory effect on nitric oxide (NO) production in LPS/IFN?-stimulated RAW264.7 cells. EAFA suppressed the production of NO in a time- and dose-dependent manner without eliciting cytotoxicity to RAW264.7 cells. To understand the molecular mechanism underlying EAFA's anti-inflammatory effect, we showed that EAFA increased total cellular anti-oxidant capacity while reducing the amount of inducible nitric oxide synthase (iNOS) in stimulated RAW264.7 cells. EAFA also suppressed the expression of IL-1? and IL-6, whereas it elevates the level of heme oxygenase-1. These EAFA-induced events were apparently associated with NF-?B and MAPK signaling pathways because the DNA binding activity of p50/p65 was impaired and the activities of both ERK and JNK were decreased in EFEA-treated cells comparing to untreated cells. Our findings suggest that EAFA exerts its anti-inflammatory effect by inhibiting the expression of iNOS. PMID:24744815

Tan, Xi; Wang, Yuan-Lai; Yang, Xiao-Lu; Zhang, Dan-Dan

2014-01-01

387

Formation of ethyl ferulate by rice koji enzyme in sake and mirin mash conditions.  

PubMed

Formation mechanism of ethyl ferulate (EF) in sake and mirin mash conditions was investigated to understand EF level control in the manufacturing process. Rice koji formed EF from ferulic acid (FA) and ethanol and decomposed EF to FA. This did not occur in sake yeast and chemical esterification was rare. Esterification of FA and hydrolysis of EF by rice koji might be due to feruloyl esterase(s). The rice koji enzyme showed normal Michaelis-Menten kinetics for FA in ethyl esterification and for EF in hydrolysis, but not for ethanol in the esterification reaction. Substrate specificity of the rice koji enzyme for hydroxycinnamic acids suggested that the main enzyme involved might be similar to type A feruloyl esterase. We studied the rice koji enzyme properties, short-term digestion of steamed rice grains with exogenous ethanol and small scale mirin making with pH adjustment. Our results suggested differences in the esterification and hydrolysis properties of the enzyme, in particular, different pH dependencies and different behaviors under high ethanol conditions; these factors might cause the differing EF levels in sake and mirin mashes. PMID:23597918

Hashizume, Katsumi; Ito, Toshihiko; Ishizuka, Takahiro; Takeda, Naoki

2013-08-01

388

Mechanistic insights into the hydrolysis of 2-chloroethyl ethyl sulfide: the expanded roles of sulfonium salts.  

PubMed

The hydrolysis of 2-chloroethyl ethyl sulfide has been examined in an effort to better understand its mechanism under more concentrated conditions. Two salts formed during hydrolysis were synthesized, and an emphasis was placed on determining their effect on the reaction as it proceeded. Unexpected changes in mechanism were seen when excess chloride was added to the reaction. By measuring rates and product distributions as the products were added back into the hydrolysis, a mechanism was developed. The formation of these sulfonium salts represents additional products in the disappearance of 2-chloroethyl ethyl sulfide with k3 in particular causing a deviation away from expected first-order behavior. Sulfonium salts 3 and 4 do not appear to interconvert, and the system as a whole had fewer pathways available than previously proposed. Initial conditions for studying the hydrolysis were very important and could lead to different conclusions depending on the conditions used. This work will aid in better understanding the hydrolysis of the very toxic chemical warfare agent mustard (bis(2-chloroethyl)sulfide) in the environment and during its decontamination. PMID:23767819

Bae, Su Y; Winemiller, Mark D

2013-07-01

389

Detection of benzene, toluene, ethyl benzene, and xylenes (BTEX) using toluene dioxygenase-peroxidase coupling reactions.  

PubMed

We have developed a simple, whole-cell bioassay for the detection of bioavailable benzene, toluene, ethyl benzene, and xylenes (BTEX) and similar compounds. A genetically engineered E. coli strain expressing toluene dioxygenase (TDO) and toluene dihydrodiol dehydrogenase (TodD) was constructed, enabling the conversion of BTEX into their respective catechols, which were quickly converted into colored products by a horseradish peroxidase (HRP)-coupled reaction. The intensity of the color formation was correlated to concentrations of the BTEX compounds. Under the optimized conditions, a detection limit (defined as three times the standard deviation of the response obtained from the blank) of 10, 10, 20, and 50 microM was observed for benzene, toluene, ethyl benzene, and xylene, respectively. The bioassay was selective toward BTEX-related compounds with no interference observed with commonly used pesticides, herbicides, and organic solvent. The bioassay was very stable with little change in response over a 10-week period. The excellent stability suggests that the reported bioassay may be suitable for field monitoring of BTEX to identify and track contaminated water and follow the bioremediation progress. PMID:14656160

Xu, Zhaohui; Mulchandani, Ashok; Chen, Wilfred

2003-01-01

390

Effects of the Ethyl Acetate Fraction of Alchornea triplinervia on Healing Gastric Ulcer in Rats  

PubMed Central

Alchornea triplinervia (Spreng.) Muell. Arg (Euphorbiaceae) is a medicinal plant commonly used by people living in the Cerrado region of Brazil to treat gastrointestinal ulcers. We previously described the gastroprotective action of methanolic extract (ME) of Alchornea triplinervia and the ethyl acetate fraction (EAF) in increasing of prostaglandin E2 (PGE2) gastric levels in the mucosa. In this work we evaluated the effect of EAF in promoting the healing process in rats with acetic acid-induced gastric ulcers. In addition, toxicity was investigated during treatment with EAF. After 14 days of treatment with EAF, the potent stimulator of gastric cell proliferation contributed to the acceleration of gastric ulcer healing. Upon immunohistochemical analysis, we observed a pronounced expression of COX-2, mainly in the submucosal layer. The 14-day EAF treatment also significantly increased the number of neutrophils in the gastric mucosa regeneration area. The EAF induced angiogenesis on gastric mucosa, observed as an increase of the number of blood vessels supplying the stomach in rats treated with EAF. Oral administration for 14 days of the ethyl acetate fraction from Alchornea triplinervia accelerated the healing of gastric ulcers in rats by promoting epithelial cell proliferation, increasing the number of neutrophils and stimulation of mucus production. This fraction, which contained mainly phenolic compounds, contributed to gastric mucosa healing.

Lima, Zeila P.; Bonamin, Flavia; Calvo, Tamara R.; Vilegas, Wagner; Santos, Lourdes C.; Rozza, Ariane L.; Pellizzon, Claudia H.; Rocha, Lucia R. M.; Hiruma-Lima, Clelia A.

2011-01-01

391

Influence of the brewing process on furfuryl ethyl ether formation during beer aging.  

PubMed

In beer, the development of a solvent-like stale flavor is associated with the formation of furfuryl ethyl ether. The synthesis rate of this important flavor compound is proportional to the concentration of furfuryl alcohol in beer. This study shows that furfuryl alcohol in beer is mainly formed by Maillard reactions initiated during wort boiling and malt production. A mechanism for its formation from alpha-(1,4)-oligoglucans and amino acids in wort and beer is proposed. During wort boiling, a quadratic relationship was found between the wort extract concentration, on the one hand, and the increase of furfuryl alcohol and furfural, on the other. The reduction of furfural by yeast during fermentation further increases the furfuryl alcohol content. In pale beers, the furfuryl alcohol concentration is essentially determined by the thermal load on wort during brewing operations. In dark beers, a considerable fraction of furfuryl alcohol may, however, come from the dark malts used. These results lead to important practical conclusions concerning the control over furfuryl ethyl ether in beer. PMID:15506813

Vanderhaegen, Bart; Neven, Hedwig; Verstrepen, Kevin J; Delvaux, Freddy R; Verachtert, Hubert; Derdelinckx, Guy

2004-11-01

392

The influence of temperature on the polymerization of ethyl cyanoacrylate from the vapor phase  

SciTech Connect

The polymerization of ethyl cyanoacrylate fumes from surface bound initiators is an important step in many novel and mature technologies. Understanding the effect of temperature on the rate of poly(ethyl cyanoacrylate) (PECA) growth and its molecular weight during its polymerization from the vapor phase from surface bound initiators provides insight into the important mechanistic aspects that impact the polymerizations success. In these studies, it is shown that the amount of PECA formed during the polymerization of ECA from a latent fingerprint increases with decreasing temperature, while the polymer molecular weight varies little. This is interpreted to be the result of the loosening of the ion pair that initiates the polymer chain growth and resides on the end of the growing polymer chain with decreasing temperature. Comparison of temperature effects and counter-ion studies show that in both cases loosening the ion pair results in the formation of more polymer with similar molecular weight, verifying this interpretation. These results further suggest that lowering the temperature may be an effective method to optimize anionic vapor phase polymerizations, including the improvement of the quality of aged latent prints and preliminary results are presented that substantiate this prediction.

Dadmun, Mark D [ORNL; Algaier, Dana [University of Tennessee, Knoxville (UTK); Baskaran, Durairaj [University of Tennessee, Knoxville (UTK)

2011-01-01

393

Kinetics of the heterogeneously catalyzed formation of tert-amyl ethyl ether  

SciTech Connect

In this work, the kinetics and equilibrium of the heterogeneously catalyzed liquid-phase formation of tert-amyl ethyl ether (TAEE) were studied. The catalyst used was a commercial sulfonic acid ion-exchange resin (Amberlyst 16W). The experiments were carried out in a continuous stirred-tank reactor, measuring stationary reaction rates. The measured reaction rates were fitted to three kinetic models; homogeneous, Eley-Rideal type, and Langmuir-Hinshelwood type. Of these, the Langmuir-Hinshelwood type model described the experimental results best. This model is based on single-site adsorption of every component, with the surface reaction being the rate-limiting step. The activation energies for the formation of tert-amyl ethyl ether from 2-methyl-1-butene were 90 and from 2-methyl-2-butene 108 kJ/mol. For the isomerization of 2-methyl-1-butene to 2-methyl-2-butene, an activation energy of 82 kJ/mol was obtained.

Linnekoski, J.A.; Krause, A.O. [Helsinki Univ. of Technology, Espoo (Finland). Lab. of Industrial Chemistry] [Helsinki Univ. of Technology, Espoo (Finland). Lab. of Industrial Chemistry; Rihko, L.K. [Neste Oy, Porvoo (Finland). Technology Center] [Neste Oy, Porvoo (Finland). Technology Center

1997-02-01

394

Inhibitory effects of plant-derived flavonoids and phenolic acids on malonaldehyde formation from ethyl arachidonate.  

PubMed

The antioxidant activities of naturally occurring plant compounds were measured in a lipid peroxidation system consisting of ethyl arachidonate and Fenton's reagent. Inhibitory effects of 24 plant-derived flavonoids and 5 phenolic acids on malonaldehyde (MA) formation from ethyl arachidonate were examined using gas chromatography (GC) with a nitrogen-phosphorus detector (NPD). Luteolin, which showed the strongest antioxidant activity, inhibited MA formation by 94% and 97% at the levels of 0.5 and 1.0 mM, respectively. The antioxidant activities of the flavones and flavonols decreased in the following order: luteolin > rhamnetin > fisetin > kaempferol > morin > quercetin. Among the flavanones tested, hesperitin, taxifolin, and naringenin exhibited appreciable antioxidant activities (61-84%) at the 1.0 mM level. The inhibitory effect of epigallocatechin gallate (82.5% at the 1.0 mM level) was the strongest among the flavan-3-ols tested. Ferulic acid had the most potent antioxidant activity (74.6% at the 1.0 mM level) of the phenolic acids tested. PMID:14611194

Lee, Kwang-Geun; Shibamoto, Takayuki; Takeoka, Gary R; Lee, Sung-Eun; Kim, Jeong-Han; Park, Byeoung-Soo

2003-11-19

395

Spectroscopic Confirmation of Ethyl Cyanide in Titan’s Atmosphere using ALMA  

NASA Astrophysics Data System (ADS)

In the last few decades, many molecular species have been detected in the atmosphere of Titan. The first detection of a new molecule on Titan using high-resolution microwave spectroscopy was by Bézard et al. (1993), who observed multiple emission lines from methyl cyanide (CH3CN) near 221 GHz. The presence of ethyl cyanide (CH3CH2CN) has long been predicted by photochemical models, and the protonated form (CH3CH2CNH+) was previously inferred from Cassini INMS measurements (Vuitton et al. 2006). Here, we present the first spectroscopic detection of ethyl cyanide in Titan's atmosphere, obtained using high spectral/spatial-resolution observations carried out with the Atacama Large Millimeter/sub-millimeter Array (ALMA). We have detected over 30 rotational emission lines from CH3CH2CN in the frequency range 220-350 GHz, and will present a preliminary model for the column density, as well as maps of the CH3CH2CN distribution in Titan's daylight hemisphere.References: Vuitton, Yelle, & Anicich 2006, ApJ, 647, L175.; Bézard, B., Marten, A., & Paubert, G. (1993). Detection of Acetonitrile on Titan. In AAS/Division for Planetary Sciences Meeting Abstracts #25.09, vol. 25 of Bulletin of the American Astronomical Society, (p. 1100).

Palmer, Maureen Y.; Cordiner, Martin A.; Nixon, Conor A.; Kisiel, Zbigniew; Charnley, Steven B.; Teanby, Nick; Kuan, Yi-Jehng; Mumma, Michael J.

2014-11-01

396

Poly[hemi(ethyl­enediammonium) [di-?-oxalato-indium(III)] dihydrate  

PubMed Central

In title compound, {(C2H10N2)0.5[In(C2O4)2]·2H2O}n, the unique InIII ion is coordinated by eight O atoms from four oxalate ligands in a distorted square-anti­prismatic environment. The doubly bis-chelating oxalate ligands act as bridging ligands connecting symmetry-related InIII ions and forming a three-dimensional open framework structure. Ethyl­enediammonium cations and water mol­ecules occupy the voids within the structure. The unique ethyl­enediammonium cation and one water mol­ecule both lie on a twofold rotation axis. One of the other two water mol­ecules residing on general crystallographic sites was refined as disordered with half occupancy. In the crystal structure, cations and water mol­ecules are linked to the anionic framework via inter­molecular O—H?O and N—H?O hydrogen bonds. PMID:21582342

Sun, Qiaozhen; Liu, Yang; Li, Hongwu; Luo, Zhi

2009-01-01

397

Analgesic and antiinflammatory activities of the ethyl acetate fraction of Bidens pilosa (Asteraceae).  

PubMed

Bidens pilosa is an Asteraceae widely used in traditional medicine for the treatment of various ailments including pain and inflammation. The present work was undertaken to assess the analgesic and antiinflammatory properties of the ethyl acetate fraction of methylene chloride/methanol (1:1) extract of leaves of Bidens pilosa at the gradual doses of 50, 100 and 200 mg/kg in mice and rats, respectively. The analgesic properties of Bidens pilosa were investigated using the acetic acid writhing, hot plate, capsaicin and formalin-induced pain models. This was followed by a study of the antiinflammatory properties using carrageenan, dextran, histamine and serotonin to induce acute inflammation in rat hind paw. The extract provided a significant (p < 0.01) reduction in pain induced by all four models of nociception. It also presented significant (p < 0.05) antiinflammatory activity in all four models of acute inflammation. These results show that the ethyl acetate fraction of methylene chloride/methanol (1:1) of Bidens pilosa has both analgesic and antiinflammatory properties. The qualitative analysis of the fraction by the high-performance liquid chromatography (HPLC) fingerprint revealed the presence of two flavonoids, namely quercetin and iso-okanin, known to have antiinflammatory and antinociceptive properties, which could be responsible for the analgesic and antiinflammatory effects observed. PMID:24242914

Fotso, Aurélien Fotso; Longo, Frida; Djomeni, Paul Désiré Dzeufiet; Kouam, Siméon Fogue; Spiteller, Michael; Dongmo, Alain Bertrand; Savineau, J P

2014-04-01

398

LABORATORY CHARACTERIZATION AND ASTROPHYSICAL DETECTION OF VIBRATIONALLY EXCITED STATES OF ETHYL CYANIDE  

SciTech Connect

Ethyl cyanide, CH{sub 3}CH{sub 2}CN, is an important interstellar molecule with a very dense rotational-vibrational spectrum. On the basis of new laboratory data in the range of 17-605 GHz and ab initio calculations, two new vibrational states, {nu}{sub 12} and {nu}{sub 20}, have been detected in molecular clouds of Orion. Laboratory data consist of Stark spectroscopy (17-110 GHz) and frequency-modulated spectrometers (GEM laboratory in Valladolid: 17-170, 270-360 GHz; Toyama: 26-200 GHz; Emory: 200-240 GHz; Ohio State: 258-368 GHz; and JPL: 270-318, 395-605 GHz). More than 700 distinct lines of each species were measured in J up to 71 and in K{sub a} up to 25. The states were fitted with Watson's S-reduction Hamiltonian. The two new states have been identified in the interstellar medium toward the Orion Nebula (Orion KL). The ground state, the isotopologues of CH{sub 3}CH{sub 2}CN, and the vibrationally excited states have been fitted to obtain column densities and to derive vibrational temperatures. All together, ethyl cyanide is responsible for more than 2000 lines in the observed frequency range of 80-280 GHz.

Daly, A. M.; Bermudez, C.; Alonso, J. L. [Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Area de Quimica-Fisica, Laboratorios de Espectroscopia y Bioespectroscopia, Unidad Asociada del CSIC, Universidad de Valladolid, E-47005 Valladolid (Spain); Lopez, A.; Tercero, B.; Cernicharo, J. [Department of Astrophysics, CAB, INTA-CSIC, Crta Torrejon, E-28850 Torrejon de Ardoz, Madrid (Spain); Pearson, J. C. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Padadena, CA 91109 (United States); Marcelino, N., E-mail: adammichael.daly@uva.es, E-mail: cbermu@qf.uva.es, E-mail: jlalonso@qf.uva.es, E-mail: lopezja@cab.inta-csic.es, E-mail: terceromb@cab.inta-csic.es, E-mail: jcernicharo@cab.inta-csic.es, E-mail: John.C.Pearson@jpl.nasa.gov, E-mail: nmarceli@nrao.edu [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States)

2013-05-01

399

Acetone and Ethyl Acetate in Commercial Nail Polish Removers: A Quantitative NMR Experiment Using an Internal Standard  

NASA Astrophysics Data System (ADS)

The qualitative and quantitative analysis of commercial nail polish removers is performed on a 60 MHz NMR spectrometer. After taking NMR spectra of the polish removers, students can make peak assignments for the known components of acetone and ethyl acetate. Using these spectra, students are also able to identify the unknown alcohol present in the remover as ethanol. Quantitative analysis of either the acetone or ethyl acetate in the nail polish removers is accomplished by comparing the analyte peak intensities with that of an internal standard. The system in which deuterated acetone is used as a solvent and methylene chloride as an internal standard gave precise results for both commercial removers and for standards prepared from pure acetone or an ethyl acetate/ethanol mixture. As recovery from the standards was approximately 96 - 98% of what was anticipated, the analysis of the commercial products is also believed to be accurate.

Clarke, David W.

1997-12-01

400

Synthesis of high specific activity [ethyl-1,2-3H]-labeled chlorpyrifos oxon and diazoxon  

SciTech Connect

[Ethyl-1,2-3H] Chlorpyrifos oxon and [ethyl-1,2-3H] diazoxon were synthesized at a specific activity of 79 and 58 Ci/mmol, respectively, by catalytic tritiation of the corresponding monovinyl analogs over Pd/C. Direct evidence is provided that the high specific activity results from isotope exchange of the terminal vinylic protons prior to saturation of the double bond. This radiosynthesis procedure is applicable to the toxicologically-important oxon metabolites of many commercial O-O-diethyl phosphorothioate pesticides.

Zhang, Nanjing; Morimoto, Hiromi; Williams, Philip G.; Casida, John E

2000-05-01

401

Kinetic resolution of ( R, S)-ethyl 2-hydroxyl-4-phenylbutyrate via lipase-catalyzed hydrolysis and transesterification in isooctane  

Microsoft Academic Search

In the enantioselective hydrolysis of (R,S)-ethyl 2-hydroxy-4-phenylbutyrate ((R,S)-EHPB) in isooctane or in a biphasic solution, Lipase PS having an enantiomeric ratio (i.e. the E value) of 22 for the (S)-enantiomer was screened as the best lipase to produce the remaining (R)-ethyl 2-hydroxy-4-phenylbutyrate ((R)-EHPB). When (R)-2-hydroxy-4-phenylbutanoic acid ((R)-HPBA) was the desired product, one might employ Novozym 435, possessing (R)-stereoselectivity with E=22,

Song-Hui Huang; Shau-Wei Tsai

2004-01-01

402

Development of a SPE-LC/MS/MS method for simultaneous quantification of baicalein, wogonin, oroxylin A and their glucuronides baicalin, wogonoside and oroxyloside in rats and its application to brain uptake and plasma pharmacokinetic studies.  

PubMed

This study aims to identify and quantify the six major bioactive flavones of the traditional Chinese medicine Scutellariae Radix (RS), including baicalein, baicalin, wogonin, wogonoside, oroxylin A and oroxyloside in rat after oral administration of a standardized RS extract. A novel, sensitive and selective method for simultaneous determination of these six analytes in rat brain and plasma using solid phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC/MS/MS) was developed and fully validated. The lower limits of quantification (LLOQs) for the six RS flavones in brain tissue were 0.02nmol/g. The LLOQs in plasma were 0.005nmol/ml for B, W and OA, 0.025nmol/ml for WG and OAG, and 0.1875nmol/ml for BG. The current study provides novel evidence of the presence of all the tested RS flavones and an isoform of BG (BG', probably baicalein-6-O-glucuronide) in the rat brain after oral administration of RS extract, suggesting their ability to permeate through the blood-brain barrier. The method was also successfully applied to the pharmacokinetic study of all these analytes in plasma after oral administration of RS extract (300mg/kg) to Sprague-Dawley rats. The developed assay method provides a useful tool for both preclinical and clinical investigations on the disposition of RS flavones in brain and plasma. PMID:24803030

Fong, Sophia Yui Kau; Wong, Yin Cheong; Zuo, Zhong

2014-08-01

403

Urinary steroid hormone analysis of ovarian cycles and pregnancy in mandrills (Mandrillus sphinx) indicate that menses, copulatory behavior, sexual swellings and reproductive condition are associated with changing estrone conjugates (E(1)C) and pregnanediol-3-glucuronide (PdG).  

PubMed

The objective of this study was to determine if sexual swellings in mandrills (Mandrillus sphinx) are a reflection of reproductive endocrine state. Urine samples were assayed using an enzyme immunoassay measuring pregnanediol-3-glucuronide (PdG) and estrone conjugates (E(1)C). Hormone patterns of ovarian cycles, pregnancy and lactation were characterized and compared with sexual swellings and copulations relative to menses and peak E(1)C. Cycle lengths averaging 28.7 days and pregnancy length of 181 days determined by hormonal and sexual swelling measures were similar to those reported in other Old World primate species. First day of copulation was observed during rising E(1)C concentrations and preceded observations of peak swelling by 1-2 days. Observations of peak sexual swellings occurred at or on the day after peak E(1)C and decreased following the ovulatory increase in PdG. Observations of menses and sexual swellings are a useful method to track mandrill ovarian cycles and can assist zoos in determining the reproductive state of females in their collections. Zoo Biol 27:320-330, 2008. (c) 2008 Wiley-Liss, Inc. PMID:19360627

Phillips, Rebecca Sellin; Wheaton, Catharine J

2008-07-01

404

Effect of ionization on infrared and electronic absorption spectra of methyl and ethyl formate in the gas phase and in astrophysical H2O ice: a computational study.  

PubMed

This work reports infrared and electronic absorption spectra of trans and gauche conformers of neutral ethyl formate, trans and cis conformers of neutral methyl formate, their ions in the gas phase, and neutral ethyl and methyl formate in astrophysical H(2)O ice. The second-order Møller-Plesset perturbation (MP2) method with TZVP basis set has been used to obtain ground-state geometries. An influence of ice on vibrational frequencies of neutral ethyl and methyl formate was obtained using integral equation formalism polarizable continnum model (IEFPCM). Significant shift in vibrational frequencies for neutral methyl and ethyl formate when studied in H(2)O ice and upon ionization is observed. Rotational and distortion constants for neutral ethyl and methyl formate from this work are in excellent agreement with the available experimental values. Electronic absorption spectra of conformers of ethyl and methyl formate and their ions are obtained using time-dependent density functional method (TDDFT). The nature of electronic transitions is also identified. We suggested lines especially good to detect these molecules in interstellar medium. Using these lines, we can identify the conformers of ethyl and methyl formate in gas phase and H(2)O ice in interstellar medium. This comparative study should provide useful guidelines to detect conformers of ethyl and methyl formate and their ions in gas phase and neutral molecules in H(2)O ice in different astronomical environment. PMID:21504217

Naganathappa, Mahadevappa; Chaudhari, Ajay

2011-05-12

405

Microbial reduction of ethyl 2-oxo-4-phenylbutyrate. Searching for R-enantioselectivity. New access to the enalapril like ACE inhibitors  

Microsoft Academic Search

Herein, different microorganisms were tested in the enantioselective reduction of ethyl 2-oxo-4-phenylbutyrate in aqueous medium for the preparation of ethyl (R)-2-hydroxy-4-phenylbutyrate, a key intermediate in the production of angiotensin converting enzyme (ACE) inhibitors. The use of Pichia angusta led to the (R)-enantiomer in 81% ee.

Paulo S. Bergo de Lacerda; Joyce Benzaquem Ribeiro; Selma G. F. Leite; Maria Antonieta Ferrara; Ricardo B. Coelho; Elba P. S. Bon; Edson Luiz da Silva Lima; O. A. C. Antunes

2006-01-01

406

Control of the solution interaction of metabisulphite and ethyl xanthate in the flotation of the Hilton ore of Mount Isa Mines Limited, Australia  

Microsoft Academic Search

An investigation of important variables which influence ethyl xanthate decomposition by sodium metabisulphite (MBS) during the laboratory flotation of Hilton ore and in plant pulps of the Hilton Concentrator has been undertaken. The decomposition of ethyl xanthate was monitored by Ultraviolet-Visible (UV-Vis) spectroscopic examination of the pulp liquid phase. Sulphur speciation in plant pulps was monitored by ion chromatographic (IC)

S. R Grano; N. W Johnson; J Ralston

1997-01-01

407

Potential Benefits of Icosapent Ethyl on the Lipid Profile: Case Studies  

PubMed Central

The cardiovascular benefits of marine-derived omega-3 fatty acids are supported by epidemiologic and clinical studies. Both healthy patients and those with confirmed coronary heart disease are advised by the American Heart Association to consume omega-3 fatty acids either through dietary fatty fish or fish oil products. We present two case reports of patients with dyslipidemia who were switched from an omega-3 dietary supplement or a prescription omega-3 drug containing eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) to a new prescription EPA-only drug, icosapent ethyl (IPE). Products containing a combination of EPA and DHA, including dietary supplements and prescription products, are more likely to increase low-density lipoprotein cholesterol (LDL-C) levels compared with pure EPA-only products. The lipid profiles of these two patients were improved with IPE treatment, illustrating the potentially favorable effects of IPE compared with other products containing both EPA and DHA. PMID:24516343

Hilleman, Daniel E.; Malesker, Mark A.

2014-01-01

408

The reaction of ethyl 2-oxo-2H-chromene-3-carboxylate with hydrazine hydrate.  

PubMed

Although salicylaldehyde azine (3) was reported in 1985 as the single product of the reaction of ethyl 2-oxo-2H-chromene-3-carboxylate (1) with hydrazine hydrate, we identified another main reaction product, besides 3, which was identified as malono-hydrazide (4). In the last two decades, however, some articles have claimed that this reaction afforded exclusively hydrazide 2 and they have reported the use of this hydrazide 2 as a precursor in the syntheses of several heterocyclic compounds and hydrazones 6. We reported herein a study of the formation of 2 and a facile route for the synthesis of the target compounds N'-arylidene-2-oxo-2H-chromene-3-carbohydrazides 6a-f. PMID:23389253

Abdel-Aziz, Hatem A; Elsaman, Tilal; Attia, Mohamed I; Alanazi, Amer M

2013-01-01

409

Continuous lipase-catalyzed production of fatty acid ethyl esters from soybean oil in compressed fluids.  

PubMed

This work investigates the continuous production of fatty acid ethyl esters from soybean oil in compressed fluids, namely carbon dioxide, propane and n-butane, using immobilized Novozym 435 as catalyst. The experiments were performed in a packed-bed bioreactor evaluating the effects of temperature in the range of 30-70 degrees C, from 50 to 150 bar, oil to ethanol molar ratio of 1:6-1:18 and solvent to substrates mass ratio of 4:1-10:1. In contrast to the use of carbon dioxide and n-butane, results showed that lipase-catalyzed alcoholysis in a continuous tubular reactor in compressed propane might be a potential route to biodiesel production as high reaction conversions were achieved at mild temperature (70 degrees C) and pressure (60 bar) conditions in short reaction times. PMID:19616937

Dalla Rosa, C; Morandim, M B; Ninow, J L; Oliveira, D; Treichel, H; Oliveira, J Vladimir

2009-12-01

410

Tunable biphasic drug release from ethyl cellulose nanofibers fabricated using a modified coaxial electrospinning process  

PubMed Central

This manuscript reports a new type of drug-loaded core-shell nanofibers that provide tunable biphasic release of quercetin. The nanofibers were fabricated using a modified coaxial electrospinning process, in which a polyvinyl chloride (PVC)-coated concentric spinneret was employed. Poly (vinyl pyrrolidone) (PVP) and ethyl cellulose (EC) were used as the polymer matrices to form the shell and core parts of the nanofibers, respectively. Scanning and transmission electron microscopy demonstrated that the nanofibers had linear morphologies and core-shell structures. The quercetin was found to be present in the nanofibers in the amorphous physical status, on the basis of X-ray diffraction results. In vitro release profiles showed that the PVP shell very rapidly freed its drug cargo into the solution, while the EC core provided the succedent sustained release. Variation of the drug loading permitted the release profiles to be tuned. PMID:24940180

2014-01-01

411

Solubility of anthracene in binary alcohol + 2-ethyl-1-hexanol solvent mixtures  

SciTech Connect

Solid-liquid equilibrium data of organic nonelectrolyte systems are becoming increasingly important in the petroleum industry, particularly in light of present trends toward heavier feedstocks and known carcinogenicity/mutagenicity of many of the larger polycyclic aromatic compounds. Experimental solubilities are reported for anthracene dissolved in seven binary mixtures containing 2-ethyl-l-hexanol with 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-octanol, 2-methyl-1-propanol, and 3-methyl-1-butanol at 25 C. Results of these measurements are used to test two mathematical representations based upon the combined nearly ideal binary solvent (NIBS)/Redlich-Kister equation and modified Wilson model. For the seven systems studied, both equations were found to provide an accurate mathematical representation of the experimental data, with an overall average absolute deviation between measured and calculated values on the order of 0.6%.

Powell, J.R.; McHale, M.E.R.; Kauppila, A.S.M.; Otero, P.; Jayasekera, M.; Acree, W.E. Jr. [Univ. of North Texas, Denton, TX (United States). Dept. of Chemistry

1995-11-01

412

Enantiopure o-ethyl phenylphosphonothioic Acid: a solvating agent for the determination of enantiomeric excesses.  

PubMed

An improved method, which is highly reproducible, was developed for the enantioseparation of racemic O-ethyl phenylphosphonothioic acid () with brucine by introducing seeding to a supersaturated solution of the diastereomeric salt mixture. The present method gave both diastereomeric salts in high yields with a diastereomeric ratio of >99.5:0.5 upon choosing the crystallization solvent (MeOH for the ( salt and MeOH/H2 O for the ( salt). The enantiopure acid showed a good chirality recognition ability for not only strong bases, such as amines and amino alcohols, but also weakly basic alcohols and was applicable as a solvating agent to the (1) H NMR determination of the enantiomeric excess of chiral amines, amino alcohols, and alcohols, including aliphatic substrates. Chirality 26:614-619, 2014. © 2014 Wiley Periodicals, Inc. PMID:24706407

Matsumoto, Kazushige; Sawayama, Jun; Hirao, Shotaro; Nishiwaki, Nagatoshi; Sugimoto, Ryuichi; Saigo, Kazuhiko

2014-10-01

413

Synthesis of ethyl N-carbobenzoxy-L-valyl-L-valyl-4-amino-3-hydroxyoctanoate  

E-print Network

with these results, ethyl N-carbobenzoxy-L-valyl-L-valyl-(3R5, 45)-4-amino-3- hydroxy-5-phenylpentanoate also was found in pre11minary testing to be a selective inhibitor of pepsin. In 1979 Liu and Glover prepared 15 the alanine-der1ved pepstatin analog, tert-butyl... white solid, which was recrystallized from ether-petroleum ether to yield 0. 22 g (87% yield): mp. 128-130'C; H NMR (90 MHz, acetone-d6) 4 0. 8-1. 0 (m, 1 34 12 H, CH3), 1. 9-2. 3 (m, 2 H, CH), 3. 9-4. 2 (m, 1 H, CH), 4. 4-4. 6 (m, 1 H, CH), 5. 0 (s...

Chesky, Elizabeth Gourley

2012-06-07

414

Antibody Conjugates of 7-Ethyl-10-Hydroxycamptothecin (SN-38) for Targeted Cancer Chemotherapy  

PubMed Central

CPT-11 is a clinically used cancer drug, and it is a prodrug of the potent topoisomerase I inhibitor, SN-38 (7-ethyl-10-hydroxycamptothecin). To bypass the need for the in vivo conversion of CPT-11 and increase the therapeutic index, bifunctional derivatives of SN-38 were prepared for use in antibody-based targeted therapy of cancer. The general synthetic scheme incorporated an acetylene-azide click cycloaddition step in the design, a short polyethylene glycol spacer for aqueous solubility, and a maleimide group for conjugation. Conjugates of a humanized anti-CEACAM5 monoclonal antibody, hMN-14, prepared using these SN-38 derivatives were evaluated in vitro for stability in buffer and human serum, and for antigen-binding and cytotoxicity in a human colon adenocarcinoma cell line. Conjugates of hMN-14 and SN-38 derivatives 16 and 17 were found promising for further development. PMID:18939816

Moon, Sung-Ju; Govindan, Serengulam V.; Cardillo, Thomas M.; D'Souza, Christopher A.; Hansen, Hans J.; Goldenberg, David M.

2009-01-01

415

Microwave-assisted dissolution and delignification of wood in 1-ethyl-3-methylimidazolium acetate.  

PubMed

Microwave irradiation can facilitate the dissolution and delignification of lignocelluloses in ionic liquids compared to simple oil bath heating as demonstrated here where 92.5% of 0.5 g ground southern yellow pine was dissolved in 10 g 1-ethyl-3-methylimidazolium acetate using microwave irradiation in only 4 min. Cellulose-rich material (pulp) regenerated from the wood/ionic liquid solution had a lignin content of ~10%; significantly lower than the lignin content of the original wood (31.9%) or that of pulp obtained from the same experiment but using 16 h of oil bath heating (16-24%). The 10% lignin content obtained with the microwave method was close to that of pulp obtained from the oil bath heating method when polyoxometalate catalysts were used (5-9%). PMID:23566466

Wang, Hui; Maxim, Mirela L; Gurau, Gabriela; Rogers, Robin D

2013-05-01

416

Ethyl mercury p-toulene sulfonanilide: Lethal and reproductive effects on pheasants  

USGS Publications Warehouse

In summary, as little as 30 parts of ethyl mercury p-toluene sulfonanilide per million (12.5 ppm of Hg) in the diet of adult pheasants was generally fatal within 2 to 3 months of feeding. Ten parts of the compound per million (4.2 ppm of Hg) in the diet reduced egg production 50 to 80 percent and increased embryo mortality in the few eggs laid. Mercury residues in 14 eggs were 0.9 to 3.1 ppm, comparable to those in eggs of pheasants fed methyl mercury dicyandiamide (3), in which hatchability was also reduced. Since similar residues of mercury have been found in eggs of wild pheasants (3) -and several species of aquatic birds (2), we conclude that mercury pollution may be sufficiently high in some areas to affect avian reproduction.

Spann, J.W.; Heath, R.G.; Kreitzer, J.F.; Locke, L.N.

1972-01-01

417

Tunable biphasic drug release from ethyl cellulose nanofibers fabricated using a modified coaxial electrospinning process.  

PubMed

This manuscript reports a new type of drug-loaded core-shell nanofibers that provide tunable biphasic release of quercetin. The nanofibers were fabricated using a modified coaxial electrospinning process, in which a polyvinyl chloride (PVC)-coated concentric spinneret was employed. Poly (vinyl pyrrolidone) (PVP) and ethyl cellulose (EC) were used as the polymer matrices to form the shell and core parts of the nanofibers, respectively. Scanning and transmission electron microscopy demonstrated that the nanofibers had linear morphologies and core-shell structures. The quercetin was found to be present in the nanofibers in the amorphous physical status, on the basis of X-ray diffraction results. In vitro release profiles showed that the PVP shell very rapidly freed its drug cargo into the solution, while the EC core provided the succedent sustained release. Variation of the drug loading permitted the release profiles to be tuned. PMID:24940180

Li, Chen; Wang, Zhuan-Hua; Yu, Deng-Guang; Williams, Gareth R

2014-01-01

418

Vasorelaxant effects of ethyl cinnamate isolated from Kaempferia galanga on smooth muscles of the rat aorta.  

PubMed

From the rhizomes of Kaempferia galanga, ethyl cinnamate (EC) was isolated and its vasorelaxant effect was examined on the rat aorta. EC inhibited the tonic contractions induced by high K+ and phenylephrine (PE) in a concentration-dependent manner, with respective IC50 values of 0.30 +/- 0.05 mM and 0.38 +/- 0.04 mM. The relaxant effect against PE-induced contractions was greater in the presence of endothelium. Pre-treatment of the aorta with methylene blue and indomethacin significantly reduced the relaxant effect. These results suggest that the inhibitory effects of EC may involve inhibition of Ca2+ influx into vascular cells and release of nitric oxide (NO) and prostacyclin from the endothelial cells. Thus, the vasorelaxant effect of EC mediated through multiple pathways may explain the traditional use of the parent plant in treating hypertension. PMID:12143006

Othman, Rozana; Ibrahim, Halijah; Mohd, Mustafa Ali; Awang, Khalijah; Gilani, Anwar-Ul Hassan; Mustafa, Mohd Rais

2002-07-01

419

Tunable biphasic drug release from ethyl cellulose nanofibers fabricated using a modified coaxial electrospinning process  

NASA Astrophysics Data System (ADS)

This manuscript reports a new type of drug-loaded core-shell nanofibers that provide tunable biphasic release of quercetin. The nanofibers were fabricated using a modified coaxial electrospinning process, in which a polyvinyl chloride (PVC)-coated concentric spinneret was employed. Poly (vinyl pyrrolidone) (PVP) and ethyl cellulose (EC) were used as the polymer matrices to form the shell and core parts of the nanofibers, respectively. Scanning and transmission electron microscopy demonstrated that the nanofibers had linear morphologies and core-shell structures. The quercetin was found to be present in the nanofibers in the amorphous physical status, on the basis of X-ray diffraction results. In vitro release profiles showed that the PVP shell very rapidly freed its drug cargo into the solution, while the EC core provided the succedent sustained release. Variation of the drug loading permitted the release profiles to be tuned.

Li, Chen; Wang, Zhuan-Hua; Yu, Deng-Guang; Williams, Gareth R.

2014-05-01

420

Macroscopic and microscopic study of 1-ethyl-3-methyl-imidazolium acetate-water mixtures.  

PubMed

Mixtures of 1-ethyl-3-methyl-imidazolium acetate ([C2mim][OAc]) and water across the entire composition range, from pure [C2mim][OAc] to pure water, have been investigated using density, viscosity, and NMR spectroscopy, relaxometry, and diffusion measurements. These results have been compared to ideal mixing laws for the microscopic data obtained from the NMR results and macroscopic data through the viscosity and density. It was also found that the mixing of the two fluids is exothermal. The proton spectra indicate though that [C2mim][OAc] and water are interacting without the formation of new compounds. The maximal deviations of experimental data from theoretical mixing rules were all found to occur within the range 0.74 ± 0.06 mol fraction of water, corresponding to approximately three water molecules per [C2mim][OAc] molecule. PMID:23020276

Hall, Craig A; Le, Kim A; Rudaz, Cyrielle; Radhi, Asanah; Lovell, Christopher S; Damion, Robin A; Budtova, Tatiana; Ries, Michael E

2012-10-25

421

CCSD(T) study of the infrared spectrum of ethyl-methyl-ether isotopic varieties  

NASA Astrophysics Data System (ADS)

Band positions for the infrared bands of various ethyl-methyl-ether isotopomers (CH 3CH 2OCH 2D, CH 2DCH 2OCH 3, CH 3CH 2OCD 3, CD 3CH 2OCH 3, CH 3CD 2OCH 3, CH 3CH 2O 13CH 3, 13CH 3CH 2OCH 3, and CH 313CH 2OCH 3) are determined using second order perturbation theory. For species showing G18 symmetry, band position are calculated variationally from a CCSD(T)/cc-pVTZ three-dimensional potential energy surface corrected vibrationally. Potential energy barriers, fundamental frequencies, and rotational constants for excited vibrational levels, are also provided. Calculated frequencies for CH 3CH 2OCD 3 confirm experimental assignments and our predictions for the most abundant isotopomer [4].

Senent, M. L.; Ruiz, R.; Villa, M.; Domínguez-Gómez, R.

2010-02-01

422

Interactions in 1-ethyl-3-methyl imidazolium tetracyanoborate ion pair: Spectroscopic and density functional study  

NASA Astrophysics Data System (ADS)

Density Functional Theory is used to investigate a weakly coordinating room-temperature ionic liquid, 1-ethyl-3-methyl imidazolium tetracyanoborate ([Emim]+[TCB]-). Four locally stable conformers of the ion pair were located. Atoms-in-molecules (AIMs) and electron density analysis indicated the existence of several hydrogen bonds. Further investigation through the Natural Bond Orbital (NBO) and Natural Energy Decomposition Analysis (NEDA) calculations provided insight into the origin of interactions in the [Emim]+[TCB]- ion pair. Strength of molecular interactions in the ionic liquid was correlated with frequency shifts of the characteristic vibrations of the ion pair. Harmonic vibrations of the ion pair were also compared with the experimental Raman and Infrared spectra. Vibrational frequencies were ass