Potential mutagenic impurities in Active Pharmaceutical Ingredient, Meropenem Trihydrate were assessed and a novel analytical method for their quantification was developed and validated. This Liquid Chromatographic me...Potential mutagenic impurities in Active Pharmaceutical Ingredient, Meropenem Trihydrate were assessed and a novel analytical method for their quantification was developed and validated. This Liquid Chromatographic method using High Resolution Mass Spectrometer (LC-HRMS) technique is proved to be suitable for simultaneous quantification of all ten identified impurities with required specificity, sensitivity, resolution, precision, accuracy, and other method characteristics as per ICH Guidelines. The acceptable limit of less than 2.9 μg/g was considered for evaluations, based on drug substance dosage and duration of treatment. The method stands most sensitive with a Limit of Detection of 0.35 μg/g, considering the challenge full acceptance criteria as per current regulatory standards.展开更多
A simple and high-throughput method to simultaneously determine selected benzodiazepines (i.e., diazepam, lorazepam, clonazepam, and bromazepam) in urine was developed and validated. The entire methodology consisted o...A simple and high-throughput method to simultaneously determine selected benzodiazepines (i.e., diazepam, lorazepam, clonazepam, and bromazepam) in urine was developed and validated. The entire methodology consisted of the application of an innovative extraction/cleanup procedure, namely liquid-liquid extraction with low-temperature partitioning (LLE-LTP), and analysis by liquid chromatography combined with high-resolution mass spectrometry (LC-HRMS). The LLE-LTP procedure was optimized via factorial design and by evaluating crucial variables, specifically the freezing mode (either slow or fast), the urine/acetonitrile volume ratio, and the sample ionic strength. The benzodiazepines were quantified using matrix-matched calibration curves where the following parameters were assessed by validation protocol: in general, linearity range of 17 - 200 μg?L–1 (r > 0.9957);limits of detection lower than 5 μg?L–1;relative standard deviations (RSD) lower than 12.5%;and accuracy ranging from 72.3 to 117%. To test this procedure’s performance, the method was applied to determine the content of diazepam in actual urine samples. The validation results obtained for the method demonstrated that the present methodology could be potentially applied in proficient laboratories as a routine approach for determining benzodiazepines compounds content in urine.展开更多
目的随着新型合成大麻素的演变,其在体内代谢速度增快,对原药的检测难度增加,为确定是否吸食合成大麻素,其生物标志物可以作为强有力的证据,常见的代谢模型有体内代谢模型和体外代谢模型。方法本研究采用液相色谱-高分辨质谱技术检测斑...目的随着新型合成大麻素的演变,其在体内代谢速度增快,对原药的检测难度增加,为确定是否吸食合成大麻素,其生物标志物可以作为强有力的证据,常见的代谢模型有体内代谢模型和体外代谢模型。方法本研究采用液相色谱-高分辨质谱技术检测斑马鱼体内代谢模型和人肝微粒体体外代谢模型中MDMB-4en-PICA的代谢情况,并使用Trance Finder 4.1通用版进行数据采集和Compound Discoverer 2.1版本进行代谢物鉴定。结果斑马鱼模型代谢产生26种代谢物,人肝微粒体模型代谢产生17种代谢物,总共32种代谢物,其中包括23种Ⅰ相代谢物和9种Ⅱ相代谢物,涉及10种代谢途径。结论结果显示,两种模型中二氢二醇代谢物(M16)的峰面积均最高,其次是羟基化代谢物(M22),而且具有一定的特异性,可以推荐作为MDMB-4en-PICA潜在的生物标志物。展开更多
A liquid chromatography-high resolution mass spectrometry （LC-HRMS） method was developed and validated for the determination of piperine （PPR） on dried blood spots （DBS）. DBS samples were prepared by spiking the...A liquid chromatography-high resolution mass spectrometry （LC-HRMS） method was developed and validated for the determination of piperine （PPR） on dried blood spots （DBS）. DBS samples were prepared by spiking the whole blood with analyte to produce 30 μL of blood spots on specimen collection cards. Chromatographic separation was achieved on an Atlantis dC18 column using acetonitrile and water （0.1% formic acid） （85：15, v/v） as mobile phase in an isocratic mode of elution at a flow rate of 0.75 mL/min. MS detection was carried out in electrospray positive ion mode for the target ions and monitored at m/z 286.1465 for PPR and 272.1303 for the internal standard （IS）. The developed method exhibited a linear dynamic range over 0.01-2000 ng/mL for PPR on DBS. The overall extraction recovery of PPR from DBS was 92.5%. Influence of hematocrit and spot volume on DBS was also evaluated and found to be well within the acceptable limits. The method was successfully applied to pharmacokinetic studies of PPR in rats.展开更多
Background: Negative experiences in early life can induce long-lasting effects on the welfare, health, and performance of farm animals. A delayed placement of chicks in rearing houses has negative effects on their per...Background: Negative experiences in early life can induce long-lasting effects on the welfare, health, and performance of farm animals. A delayed placement of chicks in rearing houses has negative effects on their performance, and results in fecal-specific odors detectable by rats. Based on this observation, the volatile organic compounds(VOCs) and metabolites from the feces of 12-day-old chickens were screened for early markers of response to negative events using gas-chromatography and liquid-chromatography coupled with mass spectrometry(GC-MS, LC-HRMS).Results: The low reproducibility of solid-phase micro-extraction of the VOCs followed by GC-MS was not suitable for marker discovery, in contrast to liquid extraction of metabolites from freeze-dried feces followed by GC-MS or LC-HRMS analysis. Therefore, the fecal metabolome from 12-day-old chicks having experienced a normal or delayed placement were recorded by GC-MS and LC-HRMS in two genotypes from two experiments. From both experiments, 25 and 35 metabolites, respectively explaining 81% and 45% of the difference between delayed and control chickens, were identified by orthogonal partial least-squares discriminant analysis from LC-HRMS and GC-MS profiling.Conclusion: The sets of molecules identified will be useful to better understand the chicks’ response to negative events over time and will contribute to define stress or welfare biomarkers.展开更多
Collagen structure in biological tissues imparts its intrinsic physical properties by the formation of several covalent crosslinks.For the first time,two major crosslinks in the skin dihydroxylysinonorleucine(HLNL)and...Collagen structure in biological tissues imparts its intrinsic physical properties by the formation of several covalent crosslinks.For the first time,two major crosslinks in the skin dihydroxylysinonorleucine(HLNL)and histidinohydroxymerodesmosine(HHMD),were isotopically labelled and then analysed by liquid-chromatography high-resolution accurate-mass mass spectrometry(LC-HRMS)and small-angle neutron scattering(SANS).The isotopic labelling followed by LC-HRMS confirmed the presence of one imino group in both HLNL and HHMD,making them more susceptible to degrade at low pH.The structural changes in collagen due to extreme changes in the pH and chrome tanning were highlighted by the SANS contrast variation between isotopic labelled and unlabelled crosslinks.This provided a better understanding of the interaction of natural crosslinks with the chromium sulphate in collagen suggesting that the development of a benign crosslinking method can help retain the intrinsic physical properties of the leather.This analytical method can also be applied to study artificial crosslinking in other collagenous tissues for biomedical applications.展开更多
Temperature,water,and light are three abiotic stress factors that have major influences on plant growth,development,and reproduction.Plants can be primed by a prior mild stress to enhance their resistance to future st...Temperature,water,and light are three abiotic stress factors that have major influences on plant growth,development,and reproduction.Plants can be primed by a prior mild stress to enhance their resistance to future stress.We used an untargeted metabolomics approach to examine Arabidopsis thaliana 11-day-old seedling’s abiotic stress responses including heat(with and without priming),cold(with and without priming),water-deficit and high-light before and after a 2-day-recovery period.Analysis of the physiological phenotypes showed that seedlings with stress treatment resulted in a reduction in fresh weight,hypocotyl and root length but remained viable.Several stress responsive metabolites were identified,confirmed with reference standards,quantified,and clustered.We identified shared and specific stress signatures for cold,heat,water-deficit,and high-light treatments.Central metabolism including amino acid metabolism,sugar metabolism,glycolysis,TCA cycle,GABA shunt,glutathione metabolism,purine metabolism,and urea cycle were found to undergo changes that are fundamentally different,although some shared commonalities in response to different treatments.Large increases in cysteine abundance and decreases in reduced glutathione were observed following multiple stress treatments highlighting the importance of oxidative stress as a general phenomenon in abiotic stress.Large fold increases in low-turnover amino acids and maltose demonstrate the critical role of protein and starch autolysis in early abiotic stress responses.展开更多
Chemical pollution in the aquatic systems of Botswana has been sparsely studied despite its potential ecological importance.Here,we perform a study of water samples collected from 13 locations distributed across Botsw...Chemical pollution in the aquatic systems of Botswana has been sparsely studied despite its potential ecological importance.Here,we perform a study of water samples collected from 13 locations distributed across Botswana to obtain the first overview of the nature and distribution of chemical contaminants across the country's aquatic environment.High resolution mass spectrometry was applied using nontargeted and suspect screening methods to qualitatively analyse samples.A total of 114 contaminants of emerging concern(CECs)were identified including 68(59.6%)pharmaceuticals and pharmaceutical metabolites;16(14.2%)pesticides;13(11.4%)psychoactive compounds and metabolites;11(9.7%)industrial chemicals and intermediates and lastly,5(4.4%)personal care products.Allopurinol,3,4-dimethylmethcathinone,and diazolidinyl urea represented the most commonly detected pharmaceutical,psychoactive drug and personal care product,respectively.The pesticide dodemorph and three industrial chemicals(stearamide,pthalic acid and bis(2-ethylhexyl)phthalate)were detected in all samples obtained.90 CECs were detected in receiving water(from 7 sample locations),75 in wastewater(from 3 sample locations)and 60 in surface water(from 9 sample locations).Of the compounds detected,only 8 had been identified in environmental samples acquired in Botswana previously.We discuss the variations in the nature and frequency of chemical pollutants detected in this work in a geographical context.The results indicate that Botswana's aquatic systems are subject to pollution,despite wastewater treatment and that in order to mitigate potentially harmful effects on both human and aquatic ecosystems,more investigations are required to correctly identify,track and tackle the sources of pollution.展开更多
文摘Potential mutagenic impurities in Active Pharmaceutical Ingredient, Meropenem Trihydrate were assessed and a novel analytical method for their quantification was developed and validated. This Liquid Chromatographic method using High Resolution Mass Spectrometer (LC-HRMS) technique is proved to be suitable for simultaneous quantification of all ten identified impurities with required specificity, sensitivity, resolution, precision, accuracy, and other method characteristics as per ICH Guidelines. The acceptable limit of less than 2.9 μg/g was considered for evaluations, based on drug substance dosage and duration of treatment. The method stands most sensitive with a Limit of Detection of 0.35 μg/g, considering the challenge full acceptance criteria as per current regulatory standards.
基金Conselho Nacional de Desenvolvimento Cientifico e Tecnologico(CNPq)and Fundacao de Amparo a Pesquisa do Estado de Minas Gerais(FAPEMIG)for financial support and research fellowships.
文摘A simple and high-throughput method to simultaneously determine selected benzodiazepines (i.e., diazepam, lorazepam, clonazepam, and bromazepam) in urine was developed and validated. The entire methodology consisted of the application of an innovative extraction/cleanup procedure, namely liquid-liquid extraction with low-temperature partitioning (LLE-LTP), and analysis by liquid chromatography combined with high-resolution mass spectrometry (LC-HRMS). The LLE-LTP procedure was optimized via factorial design and by evaluating crucial variables, specifically the freezing mode (either slow or fast), the urine/acetonitrile volume ratio, and the sample ionic strength. The benzodiazepines were quantified using matrix-matched calibration curves where the following parameters were assessed by validation protocol: in general, linearity range of 17 - 200 μg?L–1 (r > 0.9957);limits of detection lower than 5 μg?L–1;relative standard deviations (RSD) lower than 12.5%;and accuracy ranging from 72.3 to 117%. To test this procedure’s performance, the method was applied to determine the content of diazepam in actual urine samples. The validation results obtained for the method demonstrated that the present methodology could be potentially applied in proficient laboratories as a routine approach for determining benzodiazepines compounds content in urine.
文摘目的随着新型合成大麻素的演变,其在体内代谢速度增快,对原药的检测难度增加,为确定是否吸食合成大麻素,其生物标志物可以作为强有力的证据,常见的代谢模型有体内代谢模型和体外代谢模型。方法本研究采用液相色谱-高分辨质谱技术检测斑马鱼体内代谢模型和人肝微粒体体外代谢模型中MDMB-4en-PICA的代谢情况,并使用Trance Finder 4.1通用版进行数据采集和Compound Discoverer 2.1版本进行代谢物鉴定。结果斑马鱼模型代谢产生26种代谢物,人肝微粒体模型代谢产生17种代谢物,总共32种代谢物,其中包括23种Ⅰ相代谢物和9种Ⅱ相代谢物,涉及10种代谢途径。结论结果显示,两种模型中二氢二醇代谢物(M16)的峰面积均最高,其次是羟基化代谢物(M22),而且具有一定的特异性,可以推荐作为MDMB-4en-PICA潜在的生物标志物。
文摘A liquid chromatography-high resolution mass spectrometry （LC-HRMS） method was developed and validated for the determination of piperine （PPR） on dried blood spots （DBS）. DBS samples were prepared by spiking the whole blood with analyte to produce 30 μL of blood spots on specimen collection cards. Chromatographic separation was achieved on an Atlantis dC18 column using acetonitrile and water （0.1% formic acid） （85：15, v/v） as mobile phase in an isocratic mode of elution at a flow rate of 0.75 mL/min. MS detection was carried out in electrospray positive ion mode for the target ions and monitored at m/z 286.1465 for PPR and 272.1303 for the internal standard （IS）. The developed method exhibited a linear dynamic range over 0.01-2000 ng/mL for PPR on DBS. The overall extraction recovery of PPR from DBS was 92.5%. Influence of hematocrit and spot volume on DBS was also evaluated and found to be well within the acceptable limits. The method was successfully applied to pharmacokinetic studies of PPR in rats.
基金supported financially by a “crédits incitatifs” grant from the department of Animal Physiology and Livestock Systems(PHASE)at INRAa grant from the Integrated Management of Animal Health metaprogram of INRA for the “GISA-WHELP” project(www.gisa.inra.fr/en)
文摘Background: Negative experiences in early life can induce long-lasting effects on the welfare, health, and performance of farm animals. A delayed placement of chicks in rearing houses has negative effects on their performance, and results in fecal-specific odors detectable by rats. Based on this observation, the volatile organic compounds(VOCs) and metabolites from the feces of 12-day-old chickens were screened for early markers of response to negative events using gas-chromatography and liquid-chromatography coupled with mass spectrometry(GC-MS, LC-HRMS).Results: The low reproducibility of solid-phase micro-extraction of the VOCs followed by GC-MS was not suitable for marker discovery, in contrast to liquid extraction of metabolites from freeze-dried feces followed by GC-MS or LC-HRMS analysis. Therefore, the fecal metabolome from 12-day-old chicks having experienced a normal or delayed placement were recorded by GC-MS and LC-HRMS in two genotypes from two experiments. From both experiments, 25 and 35 metabolites, respectively explaining 81% and 45% of the difference between delayed and control chickens, were identified by orthogonal partial least-squares discriminant analysis from LC-HRMS and GC-MS profiling.Conclusion: The sets of molecules identified will be useful to better understand the chicks’ response to negative events over time and will contribute to define stress or welfare biomarkers.
基金financially supported by the Ministry of Business,Innovation and Employment(MBIE)through LASRA Strategic Science Investment Funding(SSIF).Grant Number LSRX1801.
文摘Collagen structure in biological tissues imparts its intrinsic physical properties by the formation of several covalent crosslinks.For the first time,two major crosslinks in the skin dihydroxylysinonorleucine(HLNL)and histidinohydroxymerodesmosine(HHMD),were isotopically labelled and then analysed by liquid-chromatography high-resolution accurate-mass mass spectrometry(LC-HRMS)and small-angle neutron scattering(SANS).The isotopic labelling followed by LC-HRMS confirmed the presence of one imino group in both HLNL and HHMD,making them more susceptible to degrade at low pH.The structural changes in collagen due to extreme changes in the pH and chrome tanning were highlighted by the SANS contrast variation between isotopic labelled and unlabelled crosslinks.This provided a better understanding of the interaction of natural crosslinks with the chromium sulphate in collagen suggesting that the development of a benign crosslinking method can help retain the intrinsic physical properties of the leather.This analytical method can also be applied to study artificial crosslinking in other collagenous tissues for biomedical applications.
基金funding provided by the NSF Plant Genome Research Program grants IOS-1238812 and IOS-1400818well as support from the University of Minnesota Informatics Institute,the Minnesota Agricultural Experiment Stationby the Gordon and Margaret Bailey Endowment for Environmental Horticulture.
文摘Temperature,water,and light are three abiotic stress factors that have major influences on plant growth,development,and reproduction.Plants can be primed by a prior mild stress to enhance their resistance to future stress.We used an untargeted metabolomics approach to examine Arabidopsis thaliana 11-day-old seedling’s abiotic stress responses including heat(with and without priming),cold(with and without priming),water-deficit and high-light before and after a 2-day-recovery period.Analysis of the physiological phenotypes showed that seedlings with stress treatment resulted in a reduction in fresh weight,hypocotyl and root length but remained viable.Several stress responsive metabolites were identified,confirmed with reference standards,quantified,and clustered.We identified shared and specific stress signatures for cold,heat,water-deficit,and high-light treatments.Central metabolism including amino acid metabolism,sugar metabolism,glycolysis,TCA cycle,GABA shunt,glutathione metabolism,purine metabolism,and urea cycle were found to undergo changes that are fundamentally different,although some shared commonalities in response to different treatments.Large increases in cysteine abundance and decreases in reduced glutathione were observed following multiple stress treatments highlighting the importance of oxidative stress as a general phenomenon in abiotic stress.Large fold increases in low-turnover amino acids and maltose demonstrate the critical role of protein and starch autolysis in early abiotic stress responses.
文摘Chemical pollution in the aquatic systems of Botswana has been sparsely studied despite its potential ecological importance.Here,we perform a study of water samples collected from 13 locations distributed across Botswana to obtain the first overview of the nature and distribution of chemical contaminants across the country's aquatic environment.High resolution mass spectrometry was applied using nontargeted and suspect screening methods to qualitatively analyse samples.A total of 114 contaminants of emerging concern(CECs)were identified including 68(59.6%)pharmaceuticals and pharmaceutical metabolites;16(14.2%)pesticides;13(11.4%)psychoactive compounds and metabolites;11(9.7%)industrial chemicals and intermediates and lastly,5(4.4%)personal care products.Allopurinol,3,4-dimethylmethcathinone,and diazolidinyl urea represented the most commonly detected pharmaceutical,psychoactive drug and personal care product,respectively.The pesticide dodemorph and three industrial chemicals(stearamide,pthalic acid and bis(2-ethylhexyl)phthalate)were detected in all samples obtained.90 CECs were detected in receiving water(from 7 sample locations),75 in wastewater(from 3 sample locations)and 60 in surface water(from 9 sample locations).Of the compounds detected,only 8 had been identified in environmental samples acquired in Botswana previously.We discuss the variations in the nature and frequency of chemical pollutants detected in this work in a geographical context.The results indicate that Botswana's aquatic systems are subject to pollution,despite wastewater treatment and that in order to mitigate potentially harmful effects on both human and aquatic ecosystems,more investigations are required to correctly identify,track and tackle the sources of pollution.
