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Barbituric Acids. VIII. 5-substituted-5-(1-pyrrolidyl)barbituric AcidsCompton, Ross Davis 08 1900 (has links)
The purpose of this investigation then was the preparation of a series of 5-substituted-5-(1-pyrrolidyl)barbituric acids in which R would consist of alkyl groups ranging in size from methyl to amyl, and other groups such as phenyl and benzyl. These compounds are to be tested elsewhere for hypnotic and anticonvulsant activity.
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The Synthesis of 5-Alkyl-5-(2-Thienylmethyl)-Barbituric AcidsScarbrough, Martha Nell 08 1900 (has links)
This thesis describes the synthesis of a series of 5-alkyl-5-(2-thienylmethyl)-barbituric acids.
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Attempted Synthesis of 5-Allyl-5-(2-Thienyl)-Barbituric AcidSkinner, Charles Gordon 08 1900 (has links)
This thesis describes attempts to synthesize 5-allyl-5-(2-thienyl)-barbituric acid as an improved anticonvulsant.
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Barbituric Acids. VII. 5-alkyl-derivatives of 5-ethoxy-barbituric AcidHyde, Harold Wayne 01 1900 (has links)
A great deal of research has been devoted in recent years to the search for new drugs for the treatment of epilepsy and related convulsive disorders. This emphasis is occasioned by the fact that no one drug is effective for all patients, and also by the fact that the toxicity of a drug varies considerably from one patient to another. Among the most effective drugs are certain members of the hydantoin and barbituric acid series. For some time there has been in progress in this laboratory an investigation of members of these two series in which a hetro atom attached directly to the hetrocyclic nucleus is introduced into the side chain at position five of these two series.
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Synthesis and Antifungal Evaluation of Barbiturate Saponins And Progress Towards Cysteinyl Metal PeptidesMadhav, Monika 17 May 2013 (has links)
Invasive fungal infections are a major threat to immune-compromised patients. There is a critical need to develop new antifungal agents because of increasing resistance to the common antifungal drugs.
In the first part of this dissertation, methods for preparation of novel barbiturate saponin as antifungals and their biological activities would be described. Barbiturates and steroidal saponins have shown remarkable antifungal activity in the biological assays. Therefore, attempts were directed to combine the barbiturate with the steroid to give novel antifungal agents. The need for extensive SAR studies and to better understand these compounds efforts were directed to synthesize novel saponin barbiturates.
Glycosylation of barbiturates was achieved under basic conditions to synthesize mono and disaccharide barbiturates. Saccharide molecules were directly introduced into the barbiturate without requiring protection and deprotection of saccharides. Efficient methods were developed for synthesis of 3β derivatized steroid derivatives containing ether, carbonate, ester and carbamate linker. Synthesized mono and disaccharide barbiturates were incorporated into the steroidal skeleton to give the novel antifungal agents. Several reaction conditions were explored to give the best yield under the most efficient reaction conditions. However, a better understanding and extensive SAR study needs to be done in order to develop more promising and potent antifungal compounds.
The second part of this dissertation describes the progress towards monocysteine metal complex synthesis and their biological activities. In this attempt, several protection deprotection strategies were explored and some novel protective groups were designed for peptide synthesis.
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Redistribuição postmortem de barbitúricos em tecidos biológicos humanos / Postmortem redistribution of barbiturates in human biological tissuesAlmeida, Rafael Menck de 07 December 2012 (has links)
Os barbitúricos são fármacos com atividade depressora do sistema nervoso central e estão relacionados com elevados números de casos de intoxicações e uso não-médico em vários países. No Brasil, a droga antiepiléptica mais encontrada em casos de intoxicação é o fenobarbital, pois os pacientes relatam que \"essa é uma substância com ação forte no cérebro\". De fato, os barbitúricos estão altamente relacionados com tentativa de suicídio e homicídio. Nesses casos existe a necessidade da quantificação dessas substâncias para correlacionar com a causa mortis. No entanto, as análises toxicológicas postmortem são de difícil execução e interpretação, pois a concentração de agentes tóxicos encontrados é bastante complexa e afetada não só pela condição de deterioração do corpo, mas também por um processo conhecido como redistribuição postmortem. Em geral, concentrações mais elevadas são encontradas no sangue situado nos sítios centrais (como o sangue coletado da cavidade cardíaca) em comparação aos níveis verificados nos vasos periféricos (como a veia femoral). Em outros casos, o tempo entre a morte e o exame postmortem é suficiente para que algumas substâncias que normalmente estariam presentes no sangue não estejam mais disponíveis neste fluido biológico. Há ainda um agravante, pois não existem valores de referências para a maioria das amostras biológicas não-convencionais, dificultando assim a interpretação dos resultados. Os exames toxicológicos devem ser realizados em amostras biológicas e tem como objetivo a avaliação da intoxicação como circunstância qualificadora do delito, como causa de periculosidade ou imputabilidade. O objetivo deste trabalho foi o desenvolvimento e aplicação de métodos de identificação de barbitúricos (butalbital, secobarbital, pentobarbital e fenobarbital) em amostras postmortem (sangue cardíaco, sangue femoral e fígado). Os analitos foram extraídos das amostras utilizando a micro extração em fase líquida (LPME), identificados e quantificados por cromatografia em fase gasosa acoplada à espectrometria de massas (GC-MS). Após o desenvolvimento e validação, os métodos analíticos foram aplicados em amostras postmortem de onze cadáveres necropsiados pelo Serviço de Verificação de Óbito da Cidade de São Paulo (SVO (SVO-USP), com suspeita de envolvimento de barbitúricos. Nove casos apresentaram resultado positivo para fenobarbital. A média da razão sangue femoral/sangue cardíaco foi de 0,91 com o desvio padrão de 0,23. Para a correlação fígado/sangue femoral a média foi de 1,17 com desvio padrão de 1,29. Os barbitúricos foram escolhidos como modelo de estudo devido à grande incidência de casos de intoxicação aguda com estes fármacos no Brasil. / Barbiturates are a class of drugs that act as central nervous system depressant and are associated with high numbers of poisoning cases and non-medical use in several countries. In Brazil, phenobarbital is the most related antiepileptic drug involved in intoxication cases. Patients report that \"this drug is a substance with strong action in the brain.\" In fact, barbiturates are highly related to attempted suicide and homicide cases, in which quantification of these substances to correlate with the possible cause of death is necessary. However, postmortem toxicological analyses are difficult to perform and interpret, because the concentration of toxic agents found is quite complex and affected not only by deterioration condition of the body but also by a process known as postmortem redistribution. In general, higher concentrations are found in the blood located in central sites (e.g. heart cavity) compared with the levels found in peripheral vessels (such as the femoral vein). In other cases, the time between death and postmortem examination is enough for some substances that would normally be present in the blood are no longer available in this biological fluid. Besides, there are few reference values for most non-conventional biological samples, making it difficult to interpret the results. The objective of this work was the development and application of methods for identification of barbiturates (butalbital, secobarbital, pentobarbital and phenobarbital) in postmortem samples (heart blood, femoral blood and liver). The analytes were extracted by using liquid-phase micro extraction (LPME) and quantified by gas chromatography-mass spectrometry (GC-MS). After the development and validation, analytical methods were applied in real cases of eleven corpses autopsied by Death Verification Service of São Paulo City (USP-SVO), with suspected of barbiturates involvement. Nine cases were positive for phenobarbital. The mean ratio of blood femoral / cardiac blood was 0.91 with a standard deviation of 0.23. For the correlation liver / femoral blood the average was 1.17 with a standard deviation of 1.29. Barbiturates were chosen as model for this study because the high incidence of cases of acute poisoning with these drugs in Brazil.
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Redistribuição postmortem de barbitúricos em tecidos biológicos humanos / Postmortem redistribution of barbiturates in human biological tissuesRafael Menck de Almeida 07 December 2012 (has links)
Os barbitúricos são fármacos com atividade depressora do sistema nervoso central e estão relacionados com elevados números de casos de intoxicações e uso não-médico em vários países. No Brasil, a droga antiepiléptica mais encontrada em casos de intoxicação é o fenobarbital, pois os pacientes relatam que \"essa é uma substância com ação forte no cérebro\". De fato, os barbitúricos estão altamente relacionados com tentativa de suicídio e homicídio. Nesses casos existe a necessidade da quantificação dessas substâncias para correlacionar com a causa mortis. No entanto, as análises toxicológicas postmortem são de difícil execução e interpretação, pois a concentração de agentes tóxicos encontrados é bastante complexa e afetada não só pela condição de deterioração do corpo, mas também por um processo conhecido como redistribuição postmortem. Em geral, concentrações mais elevadas são encontradas no sangue situado nos sítios centrais (como o sangue coletado da cavidade cardíaca) em comparação aos níveis verificados nos vasos periféricos (como a veia femoral). Em outros casos, o tempo entre a morte e o exame postmortem é suficiente para que algumas substâncias que normalmente estariam presentes no sangue não estejam mais disponíveis neste fluido biológico. Há ainda um agravante, pois não existem valores de referências para a maioria das amostras biológicas não-convencionais, dificultando assim a interpretação dos resultados. Os exames toxicológicos devem ser realizados em amostras biológicas e tem como objetivo a avaliação da intoxicação como circunstância qualificadora do delito, como causa de periculosidade ou imputabilidade. O objetivo deste trabalho foi o desenvolvimento e aplicação de métodos de identificação de barbitúricos (butalbital, secobarbital, pentobarbital e fenobarbital) em amostras postmortem (sangue cardíaco, sangue femoral e fígado). Os analitos foram extraídos das amostras utilizando a micro extração em fase líquida (LPME), identificados e quantificados por cromatografia em fase gasosa acoplada à espectrometria de massas (GC-MS). Após o desenvolvimento e validação, os métodos analíticos foram aplicados em amostras postmortem de onze cadáveres necropsiados pelo Serviço de Verificação de Óbito da Cidade de São Paulo (SVO (SVO-USP), com suspeita de envolvimento de barbitúricos. Nove casos apresentaram resultado positivo para fenobarbital. A média da razão sangue femoral/sangue cardíaco foi de 0,91 com o desvio padrão de 0,23. Para a correlação fígado/sangue femoral a média foi de 1,17 com desvio padrão de 1,29. Os barbitúricos foram escolhidos como modelo de estudo devido à grande incidência de casos de intoxicação aguda com estes fármacos no Brasil. / Barbiturates are a class of drugs that act as central nervous system depressant and are associated with high numbers of poisoning cases and non-medical use in several countries. In Brazil, phenobarbital is the most related antiepileptic drug involved in intoxication cases. Patients report that \"this drug is a substance with strong action in the brain.\" In fact, barbiturates are highly related to attempted suicide and homicide cases, in which quantification of these substances to correlate with the possible cause of death is necessary. However, postmortem toxicological analyses are difficult to perform and interpret, because the concentration of toxic agents found is quite complex and affected not only by deterioration condition of the body but also by a process known as postmortem redistribution. In general, higher concentrations are found in the blood located in central sites (e.g. heart cavity) compared with the levels found in peripheral vessels (such as the femoral vein). In other cases, the time between death and postmortem examination is enough for some substances that would normally be present in the blood are no longer available in this biological fluid. Besides, there are few reference values for most non-conventional biological samples, making it difficult to interpret the results. The objective of this work was the development and application of methods for identification of barbiturates (butalbital, secobarbital, pentobarbital and phenobarbital) in postmortem samples (heart blood, femoral blood and liver). The analytes were extracted by using liquid-phase micro extraction (LPME) and quantified by gas chromatography-mass spectrometry (GC-MS). After the development and validation, analytical methods were applied in real cases of eleven corpses autopsied by Death Verification Service of São Paulo City (USP-SVO), with suspected of barbiturates involvement. Nine cases were positive for phenobarbital. The mean ratio of blood femoral / cardiac blood was 0.91 with a standard deviation of 0.23. For the correlation liver / femoral blood the average was 1.17 with a standard deviation of 1.29. Barbiturates were chosen as model for this study because the high incidence of cases of acute poisoning with these drugs in Brazil.
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Validation and comparison of three sample preparation techniques for quantitation of amobarbital, butalbital and phenobarbital in blood and urine using UFLC-MS/MSChan, Chi Hin 09 October 2019 (has links)
This research study successfully completed three objectives: 1) validate liquid-liquid, supported-liquid, and solid-phase extractions for the quantitation of three barbiturates (amobarbital, butalbital, and phenobarbital) in blood and urine using liquid chromatography-tandem mass spectrometry; 2) to compare the efficiency and effectiveness among methods in accomplishing extraction of barbiturates under the laboratory setting at Boston University School of Medicine; and 3) to report all the analytical data to RTI International for interlaboratory comparison.
For the validation study, a six-point linear calibration model (20-2000 ng/mL) with inversely weighted concentration (1/x) was reproducible in all three sample preparation methods for both blood and urine with r2 greater than or equal to 0.994. Bias and precision evaluated from three controls throughout the range of the curve were within ±20% and ±20%CV, respectively. Neither carryover nor interference was observed. Detection limits were evaluated down to 5 ng/mL depending on the extraction procedure. Samples were able to be diluted up to 50 times prior to instrumental analysis. Samples were stable on autosampler at room temperature up to 72 hours after their initial analysis. Recovery of barbiturates from blood and urine all ranged from 45% to 86%. The effect of ionization suppression or enhancement was found to have minimal impact on the validation.
For choosing the most suitable method quantifying barbiturates, efficiency and effectiveness were studied. Efficiency evaluates the time and ease of sample preparation required to prepare a sample for analysis. Supported-liquid extraction was found to be the most efficient method for extracting barbiturates as it required the least amount of time to perform and could be easily automated with minimal training. Effectiveness is an assessment of one’s ability to selectively recover target analyte at a reasonably low concentration. By considering a method’s recovery, extract cleanliness, detection limits, and reproducibility, liquid-liquid extraction was the best at quantifying barbiturates in blood and supported-liquid extraction was the most suitable method for extracting barbiturates from urine.
For interlaboratory comparison, all the data collected has been reported to RTI International. These findings can be used for examining the overall reliability and reproducibility of the validated methods. Results obtained can also be used to explore the possibility for streamlining sample preparation in the forensic laboratory, and hence reducing the case backlog.
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Application of Micellar Electrokinetic Capillary Chromatography to Forensic Analysis of Barbiturates in Biological FluidsFerslew, K. E., Hagardorn, A. N., McCormick, W. F. 01 January 1995 (has links)
Micellar electrokinetic capillary chromatography (MECC) is a form of capillary zone electrophoresis. Addition of a surfactant produces micelles in an aqueous/organic buffer. Separation of drugs is obtained via differences in the electrophoretic mobilities of the analytes within the capillary, resulting from their electrophoretic velocity and the electroosmotic flow of the buffer in a given electric field. The migration order is determined by the differential partitioning of the drugs between the micelles and the aqueous/organic phase. Barbiturates were extracted from various biological fluids at pH 4.5 with TOXI-TUBES B. MECC analyses were performed using a Waters Quanta 4000 Capillary Electrophoretic System with a 745 Data Module with a 75 μ x 60 cm capillary and an aqueous/organic buffer of 85% 10 mM borate, 10 mM phosphate, 100 mM sodium dodecyl sulfate and 15% acetonitrile at a pH of 8.5 with a voltage of 20 kV using ultraviolet absorption detection at 214 nm. Migration times were: phenobarbital, 7.78 min.; butalbital, 8.01 min.; butabarbital, 8.23 min.; mephobarbital (internal standard), 8.88 min.; amobarbital, 9.41 min.; pentobarbital, 10.03 min. and secobarbital, 10.79 min. Correlation coefficients (r) between peak areas and concentration ranges of 3 to 60 μg/mL were from 0.964 to 0.999. Coefficients of variation (CV) raged from 2.6 to 8.6% between days and 2.3 to 9.8% within day. Application of this methodology to four forensic cases of butalbital intoxication detected concentrations of 0.7 to 12.7 μg/mL in blood; 0.8 to 1.9 μg/mL in vitreous humor and 1.5 to 7.6 μg/mL in urine. MECC is applicable to forensic analysis of barbiturates extracted from biological fluids.
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Oberflächenmodifizierung von Metallen und Metalloxiden mit wasserlöslichen Polymeren und Charakterisierung der Adsorbate mit solvatochromen SondenmolekülenSeifert, Susan 05 July 2011 (has links) (PDF)
Gegenstand der vorliegenden Arbeit ist die Oberflächenmodifizierung von drei industriell bedeutenden Metallen, Eisen, Zink und Kupfer, sowie den Oxiden von Zink und Eisen, mit wasserlöslichen Polyvinyl-formamid-Polyvinylamin-Copolymeren (PVFA-co-PVAmen). Der Einfluss des pH-Wertes, des Hydrolysegrades der PVFA-co-PVAme, und der Einfluss von im wässrigen Medium ablaufenden Redoxprozessen an den Metalloberflächen auf die adsorbierte Polymermenge, wurden studiert. Ferner werden polymeranaloge Reaktionen des PVAms bzw. PVAm-modifizierter Metall- und Metalloxidpulver mit Kohlendioxid, ein Multischichtaufbau mit PVAm und Natriumpolyacrylat, als auch die Hydrophobierung durch Maleinsäureanhydridcopolymere beschrieben. Zur Charakterisierung der polymermodifizierten Oberflächen wurde die XPS, die DRIFT-Spektroskopie und die Sorptiochromie genutzt. Besonders der Sorptiochromie wurde aufgrund der hohen Sensitivität ein hoher Stellenwert in der vorliegenden Arbeit eingeräumt. Das Konzept der Sorptiochromie wurde zum ersten Mal auf Metalloberflächen angewendet. Ein zweiter zentraler Aspekt der Arbeit war deshalb die Suche nach Sondenmolekülen, die geeignet waren Polaritätsparameter farbiger Metalloxid- und Metallpulver zu ermitteln. Hierfür wurden das solvatochrome und acidochrome Verhalten, sowie die Wechselwirkungen von Barbituratfarbstoffen mit Merocyaninstruktur mit Metallionen, Metall- und Metalloxidoberflächen studiert.
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