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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Susceptibilidad in vitro de levaduras del género cándida aisladas de un grupo de pacientes con candidiasis oral frente a azoles y polienos

Torrealba Durán, Claudia Cecilia January 2007 (has links)
Trabajo de Investigación Requisito para optar al Título de Cirujano Dentista / Autor no autoriza el acceso a texto completo de su documento / Las infecciones fúngicas son comúnmente provocadas por hongos del género Candida.(6) C.albicans es la especie más frecuente(17)y en menor proporción otras como:glabrata, tropicalis y krusei. (8) Candida dubliniensis es una nueva especie identificada recientemente de cavidad oral en pacientes VIH.Estudios recientes muestran un notable incremento en el diagnóstico de Candidiasis orales(8),debido a diferentes factores facilitadores.(5,9) Así,el objetivo de este trabajo fue determinar la susceptibilidad “in vitro” de levaduras del género Candida, aisladas de pacientes chilenos con Candidiasis oral, a Nistatina, Fluconazol, Itraconazol y Voriconazol.Nuestra hipótesis plantea que la susceptibilidad de levaduras del género Candida, (Candida albicans y Candida no albicans,) aisladas de pacientes con Candidiasis oral dependen tanto de la especie de Candida como del antifúngico empleado (Azoles y Polienos). El estudio incluyó 74 cepas tales como; 41 Candida albicans,16 Candida dubliniensis,6 Candida glabrata,4 Candida famata,3 Candida krusei, 2 Candida lusitanie y 1 Candida.parapsilosis agrupadas en Candida albicans y Candida no albicans (n=33) que fueron evaluados por el método de microdilución en caldo según el documento M27-A (NCCLS)(13) Candida albicans (n=41)fueron sensibles a Fluconazol y 27 (n=33) Candida no albicans.Las especies no sensibles a Fluconazol fueron albicans, glabrata y krusei.38 Candida albicans (n=41) y 26 cepas de Candida no albicans (n=33) fueron sensibles a Itraconazol.Las especies no sensibles a Itraconazol fueron albicans, glabrata, lusitanie y dubliniensis . Las 74 especies, tanto Candida albicans como Candida no albicans, fueron sensibles a Voriconazol y Nistatina. Con el análisis estadísticos se concluyó que la susceptibilidad de levaduras del género Candida, agrupadas en Candida albicans y Candida no albicans, aisladas de pacientes chilenos con Candidiasis oral, depende tanto de la especie de Candida como del antifúngico empleado (Azoles y Polienos). (p=0,014).
2

Malononitriles and cyanoacetamides containing isoxazoles and isoxazolines

Moores, Lee C. 13 August 2011 (has links)
Isoxazoles and isoxazolines have been shown in the literature to be an important scaffold for pharmaceuticals and insecticides, as well as a source of synthetic versatility important to many syntheses. As a substitute for other aromatic rings, isoxazoles are known to change the efficacy of a given compound. Isoxazolines can be used as a precursor to many other functional moieties that may be effected during earlier synthetic steps. There are many routes to the heterocyclic moiety, allowing for their insertion in a wide range of molecules. Our group has previously reported a condensation of arylaldehydes with hydroxylamine to first make an aryloxime which can, after generating the nitrile oxide, then cyclize with an alkene or alkyne in situ and create the isoxazoline or isoxazole, respectively. The Knoevenagel Condensation reaction is identified as the addition of an activated methylene complex, malononitrile or cyanoacetamide, with a carbonyl followed by dehydration.. Our group has previously reported a facile, one-pot reductive alkylation of benzyl malononitriles. These compounds have been noted as having many insecticidal uses, as well as being potent pharmacophores. The scope of this project is to further explore and optimize the condensation of aryl aldehydes and methylene complexes. The condensed and reduced methylene complex will then be alkylated to join the heterocyclic moiety to reach the final disubstituted methylene product. A second approach will also be explored in which the monosubstituted malononitrile will first be alkylated with allyl or propargyl bromide, which can then undergo a 1,3-dipolar cycloaddition with a nitrile oxide. The library of compounds generated will be sent to collaborators to test the biological activity of the molecules. / Introduction and background literature -- Reactions of methylene complexes -- Synthesis of disubstituted methylene complexes. / Department of Chemistry
3

Novel synthesis of tripodal borate ligands

Sanchez Perucha, Alejandro January 2007 (has links)
Poly(azolyl)borate ligands have proven to be extremely popular ligands since their introduction by Trofimenko in the late 60´s. The basic skeleton of these ligands involves usually three heterocycle units linked to a central boron apex via the azole nitrogen atoms. These ligands have been applied in diverse research areas such as homogeneous catalysis, materials science and bio-inorganic chemistry. More than 2000 papers, including books and reviews regarding the properties of these compounds, have been published. However, only a few synthetic methods for the preparation of such ligands have been reported and only a few examples of chiral borate-centred ligands are known. This thesis deals with the development of a novel synthetic route to tripodal borate ligands using B(NMe2)3 as the boron source. The mechanism of the reaction of this borane with azole heterocycles has been established by exploring the reactivity of a range of azoles. One of the major features of this new synthetic protocol is that it allows the formation of chiral tripodal ligands where the chiral groups are located either at the forth position at the boron atom or at the azole heterocycles. Coordination studies of the ligands have been undertaken and the metal complexes have been studied by a combination of spectroscopic and X- ray diffraction techniques. Preliminary application of the most representative ligands in the Asymmetric Transfer Hydrogenation (ATH) of prochiral ketones has been undertaken in collaboration with Prof. Dieter Vogt at the Technical University of Eindhoven.
4

Transcriptional regulation of azole antifungal resistance in candida albicans

Liu, Teresa T., January 2008 (has links) (PDF)
Thesis (M.S.)--University of Tennessee Health Science Center, 2008. / Title from title page screen (viewed on July 31, 2008). Research advisor: P. David Rogers, Pharm.D., Ph.D. Document formatted into pages (xii, 172 p. : ill.). Vita. Abstract. Includes bibliographical references (p. 98-115).
5

Transcriptional regulation of azole antifungal resistance in candida albicans

Liu, Teresa T., January 2008 (has links) (PDF)
Thesis (Ph.D.)--University of Tennessee Health Science Center, 2008. / Title from title page screen (viewed on Septeber 9, 2008). Research advisor: P. David Rogers, Pharm.D., Ph.D. Document formatted into pages (xiii,172 p. : ill.). Vita. Abstract. Includes bibliographical references (p. 98-115).
6

New Reactions Using Diazo Intermediates Generated from Azole Compounds / アゾール類から生成するジアゾ中間体を利用する新反応

Nakamuro, Takayuki 26 March 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21126号 / 工博第4490号 / 新制||工||1698(附属図書館) / 京都大学大学院工学研究科合成・生物化学専攻 / (主査)教授 村上 正浩, 教授 杉野目 道紀, 教授 松田 建児 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM
7

Investigating FDA-Approved Drugs for Treatment of Multidrug-Resistant Neisseria gonorrhoeae

Liang, Hsin-Wen 05 June 2023 (has links)
Neisseria gonorrhoeae, the causative agent of gonorrhea, is the second most prevalent sexually transmitted infection that leads to substantial morbidity and economic burden worldwide. Improperly treated or untreated gonorrhea can lead to severe and life-threatening complications, including abortion, infertility, pelvic pain, and maternal death. Neisseria gonorrhoeae has developed resistance to the formally and currently used antibiotics. The Centers for Disease Control and Prevention (CDC) have listed multi-drug resistant N. gonorrhoeae as an urgent threat that promptly requires the development of novel therapeutic agents. Traditional drug discovery and development is a time-consuming and costly process associated with high risks. To address the dire need to replenish the dry pipeline of anti-gonorrhea medications, drug repurposing is a promising approach. In this study, an FDA-approved drug library was screened, and 14 drugs were found to exhibit promising anti-gonococcal activity. Interestingly, three extremely potent and narrow-spectrum novel candidates, itraconazole, isavuconazole, and ravuconazole, are azole antifungals, and their activities were further investigated in vitro. Of the three azoles, ravuconazole displayed the most potent activity against N. gonorrhoeae clinical isolates. The time-kill assay revealed that the three azoles showed bactericidal activity. All three azole drugs showed a low frequency of resistance. Besides, isavuconazole and ravuconazole have a longer post-antibiotic effect than azithromycin. All three azoles cleared the burden of intracellular N. gonorrhoeae completely, which is superior to ceftriaxone. In conclusion, itraconazole, isavuconazole, and ravuconazole merit future investigation for the development of anti-gonorrheal therapeutics. This study provided unexplored avenues and promising opportunities that can be further evaluated to combat N. gonorrhoeae infection. / Master of Science / Neisseria gonorrhoeae, the causative agent of gonorrhea, is the second most prevalent sexually transmitted infection that leads to substantial morbidity and economic burden worldwide. Improperly treated or untreated gonorrhea can lead to severe and life-threatening complications, including abortion, infertility, pelvic pain, and maternal death. Due to the increasing prevalence of drug resistance against the formally and currently used antibiotics, the Centers for Disease Control and Prevention (CDC) have classified multi-drug resistant N. gonorrhoeae as an urgent-threat pathogen. Therefore, the discovery of new anti-gonorrheal therapeutics is an urgent need. Drug repurposing is the process of discovering new therapeutic uses for approved or investigational drugs that go beyond the original medical indication. To address the dire need to replenish the dry pipeline of anti-gonorrheal drugs, repurposing FDA-approved drugs is a promising approach as it significantly reduces the time and expense associated with traditional drug development. By screening an FDA-approved drug library, 14 drugs were found to display promising anti-gonococcal activity. Interestingly, three (itraconazole, isavuconazole, and ravuconazole) out of 14 identified drugs were azole antifungal drugs, and their activities were further investigated in vitro. All three azole drugs showed bactericidal activity, meaning that they killed bacteria, had a low propensity to develop resistance, and completely cleared the burden of intracellular N. gonorrhoeae. Besides, our findings suggested that isavuconazole and ravuconazole possessed exceptional activity in the suppression of bacterial growth following brief antibiotic exposure. In conclusion, the three azole drugs exhibited potent anti-gonococcal activity and merited further investigation. This study provided unexplored avenues and promising opportunities that can be further evaluated to combat multidrug-resistant N. gonorrhoeae. Neisseria gonorrhoeae, the causative agent of gonorrhea, is the second most prevalent sexually transmitted infection that leads to substantial morbidity and economic burden worldwide. Improperly treated or untreated gonorrhea can lead to severe and life-threatening complications, including abortion, infertility, pelvic pain, and maternal death. Due to the increasing prevalence of drug resistance against the formally and currently used antibiotics, the Centers for Disease Control and Prevention (CDC) have classified multi-drug resistant N. gonorrhoeae as an urgent-threat pathogen. Therefore, the discovery of new anti-gonorrheal therapeutics is an urgent need. Drug repurposing is the process of discovering new therapeutic uses for approved or investigational drugs that go beyond the original medical indication. To address the dire need to replenish the dry pipeline of anti-gonorrheal drugs, repurposing FDA-approved drugs is a promising approach as it significantly reduces the time and expense associated with traditional drug development. By screening an FDA-approved drug library, 14 drugs were found to display promising anti-gonococcal activity. Interestingly, three (itraconazole, isavuconazole, and ravuconazole) out of 14 identified drugs were azole antifungal drugs, and their activities were further investigated in vitro. All three azole drugs showed bactericidal activity, meaning that they killed bacteria, had a low propensity to develop resistance, and completely cleared the burden of intracellular N. gonorrhoeae. Besides, our findings suggested that isavuconazole and ravuconazole possessed exceptional activity in the suppression of bacterial growth following brief antibiotic exposure. In conclusion, the three azole drugs exhibited potent anti-gonococcal activity and merited further investigation. This study provided unexplored avenues and promising opportunities that can be further evaluated to combat multidrug-resistant N. gonorrhoeae.
8

1.Pyrolytic Studies of Arylimines 2.Synthetic Studies of Natural Products With 2-Phenylbenzofuran framework by the Flash Vacuum Pyrolysis 3.Pyrolytic Studies of Furylmethyl benzoates¡BBenzothienylmethyl benzoates and N-Methylpyrrolylmethyl benzoates

Hsueh, Yu-Tan 07 September 2011 (has links)
The thesis is divided into three chapters Chapter 1¡BFlash vacuum pyrolysis of 2-chloro-N-arenylideneaniline gave quinolines by the intromolecular cyclization. And then, flash vacuum pyrolysis of 2-methoxy-N-arenylideneaniline gave the benzothiazole products by the bond cleavage and the radical reaction. Chapter 2¡BFlash vacuum pyrolysis of 32 gave Stemofuran C. And then, flash vacuum pyrolysis of 33 gave 31 which belonging to the former compound of E6 reported on the paper. We also found that we also could get 2-phenylbenzofuran by flash vacuum pyrolysis of 44. Chapter 3¡BFlash vacuum pyrolysis of furylmethyl benzoates¡Bbenzo- thienylmethyl benzoates and N-methylpyrrolylmethyl benzoates gave the corresponding products by the interconversion between vinylcarbene and cyclopropene.
9

Hétérocycles pentaatomiques synthèses organiques, études des propriétés inhibitrices de la corrosion et des propriétés complexantes /

Bentiss, Fouad Lagrenée, Michel. January 2007 (has links)
Reproduction de : Habilitation à diriger des recherches : Sciences physiques. Chimie : Lille 1 : 2006. / N° d'ordre (Lille 1) : 522. Résumé. Titre provenant de la page de titre du document numérisé. Bibliogr. à la fin de chaque chapitre.
10

Tuning the reactivity of mononuclear tridentate platinum (II) complexes : a detailed kinetic and mechanistic approach using Azole Nucleophiles.

Nkabinde, Slindokuhle V. 04 September 2014 (has links)
The kinetic substitution reactions of two different sets of mononuclear Platinum(II) complexes with heterocyclic bio-relevant azole nucleophiles, viz. Imidazole (Im), 1-methylimidazole (MIm), 1,2-Dimethylimidazole (DIm), 1,2,4-triazole (Trz) and pyrazole (Pyz). All substitution reactions were studied under pseudo-first order conditions as a function of the incoming nucleophiles concentration and temperature using stopped-flow techniques and UV/Visible spectroscopy. The first set of complexes included the tridentate polypyridine complexes, Pt(II)(2,2:6,2″-terpyridine)Cl]Cl.2H2O, (PtL1) Pt(II)(1,3-di(2-pyridyl)benzene)Cl, (PtL2) Pt(II)(2,6-di-(2’-quinolinyl)pyridine)Cl](Cl), (PtL3) and Pt(II)(1,3-di-(2’-quinolinyl)benzene)Cl (PtL4). The substitution of these complexes with the previously mentioned azoles showed that tuning electronic communication of the Pt(II) centre towards substitution through quinoline moieties has an opposed effect to that obtained through pyridine moieties, and verified that the trans-effect of a phenyl ring is much greater than that of a pyridine ring. The reactivity trend among the complexes was PtL2 > PtL4 > PtL1 > PtL3. Once the nucleophiles were categorised into two groups based on their structural similarities, reactivity trend observed amongst the nucleophiles was generally Im > Pyz > Trz, based on the basicity (electronic effects) and MIm > Im > DIm based on steric effects. The second series of complexes were tridentate [Pt(bis(2-pyridylmethyl)amine)OH2](ClO4)2, Ptdpa and [Pt(bis(2-pyridylmethyl)sulfide)OH2](ClO4)2, Ptdps of which the kinetics were studies in an aqua medium and at constant ionic strength (0.1 M). Ptdps was found to be more reactive (three magnitude higher) than Ptdpa. The rate of substitution of the aqua ligand is dependent on the strength of the σ-donor character and the π-acceptability of the atom situated trans to the leaving group. The observed reactivity for the azoles followed the trend, MIm > Im > DIm > Trz > Pyz. This reactivity trend is in accordance with the basicity, and reflects steric and electrophilic effects of the nucleophiles. This was supported by DFT calculations and the X-ray crystal structure of Ptdps_Cl. For all substitution reactions, the temperature dependent studies showed an associative activation. It is envisaged that the findings of this project will provide useful information for designing new drugs as part of a protracted search of effective anticancer drugs with a wider spectrum. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2014.

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