Rozprawy doktorskie: „Fura-2”

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Silva, Orivaldo Lopes da. "Incorporação de cálcio iônico em células ósseas induzida por campo elétrico". Universidade de São Paulo, 1995. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-10062014-163725/.

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Acredita-se que sinais elétricos endógenos afetem remodelamento, metabolismo, reparo e crescimento ósseos. Existe uma ampla literatura que trata do efeito de sinais elétricos externos sobre as respostas de síntese, mitogênese e proliferação em osteoblastos e células ósseas in vitro. Acredita-se que as respostas fisiológicas ao estimulo elétrico sejam devidas a mecanismos celulares que envolvem variações na concentração citosólica de cálcio. No presente estudo esse efeito celular foi observado através da estimulação direta, por campo elétrico de intensidade fisiologicamente significativa de 10mV/cm e frequência 1,5 MHz, de células ósseas em cultura primária obtidas a partir da calota calvária de ratos da raça Sprague-Dawley. Os mecanismos de transdução do campo elétrico são investigados pela mensuração em tempo real do efeito do campo elétrico na concentração citosólica de Ca2+ utilizando-se técnica de fluorescência de Fura-2, em um sistema que permite a medida em células individuais. As estimulações elétricas resultaram em variações significativas na concentração de cálcio citosólico. Mais especificamente, observou-se um aumento na amplitude e na duração das oscilações de cálcio iônico, com tempos de latência variáveis para as células estudadas.
Endogenous electrical signals have been thought to affect bone remodeling, metabolism, healing and growth. Much literature exists concerning the effect of external electrical signals on synthetic, mitogenic, and proliferative responses of osteoblasts or osteoblast-like cells in vitro. Physiological responses to electrical stimulation are thought to be due to cellular mechanisms involving cytosolic calcium concentration changes. In this study this cellular effect was observed by directly stimulating primary culture bone cells from Sprague-Dawley rat calvaria at physiological significant field strength of 10 mV/cm and frequency 1,5 MHz. Electric field transduction mechanisms are investigated by measuring the real-time electric field effect on cytosolic Ca+2 concentrations using Fura-2 fluorescence technology in a system capable of measurement on a cell-by-cell basis. The electrical stimulations resulted in significant changes in cytosolic calcium concentration. More specifically, an increase was noted in calcium oscillation amplitude and duration, and a variable response latency period for the cells studied.

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Hadrovic, Banina. "A study of TRPV1 and TRPV4 ion channels in the beta cells by using fura-2 based microfluorometry". Thesis, Mälardalen University, School of Sustainable Development of Society and Technology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-7350.

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The calcium ion (Ca²⁺) is an important ion that regulates many cellular functions including exocytosis, contraction of muscles, neural functions, fertilization and cell division. In the plasma membrane of cells there are different Ca²⁺ channels, including the transient receptor potential (TRP) family of cation channels. The TRP channels are activated by physical stimuli like temperature, stretch, osmolality, and also various ligands. These channels are divided into seven subfamilies, namely TRPC, TRPV, TRPM, TRPML, TRPA, TRPP, and TRPN.

TRP channels can regulate the cytoplasmic free Ca²⁺ concentration ([Ca²⁺]_i) and are therefore important for research of insulin secretion from beta (β) cells. With TRP research new and more effective treatment methods for people with diabetes can be developed. People with type 2 diabetes have a decreased insulin secretion from beta (β) cells, in response to glucose. Cytoplasmic free Ca²⁺ concentration ([Ca²⁺]_i) is important for insulin secretion. It is therefore desirable to find compounds that can increase [Ca²⁺]_i in pancreatic β cells and thereby increase insulin secretion.

The aim of this project was to investigate whether pancreatic β cells express TRPV1 and TRPV4 ion channels. If the channels are expressed in β cells the [Ca²⁺]_ican be increased by identifying substances that stimulate TRPV1 and TRPV4 channels. The results can then be used for providing better treatment for patients with diabetes type 2. Insulinoma cells from rat (S5 cells) were used as a model for β cells. [Ca²⁺]_i was measured from single fura-2 loaded S5 cells by ratiometric microfluorometry. To test whether TRPV1 is expressed,

N-(4-hydroxyphenyl)-Arachidonoylamide (AM404) and [5-hydroxyl-1-(4-hydroxy-3-methoxyphenyl)decan-3-one] ([6]-gingerol) were used. To test whether TRPV4 was expressed, a TRPV4-selective agonist 4alpha-Phorbol 12,13-Didecanoate namely 4α–PDD was used.

The two agonist of TRPV1, AM404 and [6]-gingerol increased [Ca²⁺]_i. Capsaicin a classical activator of TRPV1 used as a control also increased [Ca²⁺]_i. These increases were inhibited by capsazepine, a specific blocker of TRPV1. 4α–PDD, a specific agonist of TRPV4 also increased [Ca²⁺]_i. These results suggest that S5 cells express both TRPV1 and TRPV4 channels and that AM404, [6]-gingerol and 4α–PDD are potential substances for increasing the insulin secretion from β cells.

Kalciumjonen (Ca²⁺) är en viktig jon och förmedlar signaler i processer som cellutsöndring, muskelkontraktion, nervfunktion, fertilisering och celldelning. I cellers plasmamembran finns det olika sorters Ca²⁺ -kanaler, inklusive transient receptor potential (TRP) jonkanalerna. TRP kanalerna aktiveras av fysisk stimulans, så som temperatur, utsträckning, osmolalitet men också av olika ligander. TRP kanalerna är indelade i sju underfamiljer, TRPC, TRPV, TRPM, TRPML, TRPA, TRPP,och TRPN.

TRP kanalerna reglerar den fria Ca²⁺ koncentrationen ([Ca²⁺]_i) i cytoplasman och är därmed viktiga för forskning inom insulinutsöndringen från beta (β) celler. Med denna forskning kan nya och effektivare behandlingsmetoder för personer med diabetes utvecklas. Personer med typ 2 diabetes har bl.a. en minskad insulinfrisättning i beta (β) celler som orsakar en glukosökning i blodet. Den fria Ca²⁺-koncentrationen ([Ca²⁺]_i) i cytoplasman är viktig för insulinfrisättningen. Det är därför önskvärt att hitta kemiska föreningar som kan bidra till en ökning av [Ca²⁺]_i i bukspottkörtelns β celler och därmed också ge en ökad insulinfrisättning.

Målet med detta projekt har varit att undersöka om β celler från bukspottkörtel uttrycker jonkanalerna TRPV1 och TRPV4. Om β celler uttrycker dessa kanaler kan [Ca²⁺]_ii cytoplasman ökas genom att identifiera substanser som stimulerar just TRPV1 och TRPV4 kanaler. Resultaten kan användas för att bidra med bättre behandling till diabetespatienter med typ 2 diabetes. Tumoriserade celler från råtta (S5) användes som modell för β celler. [Ca²⁺]_i mättes från enskilda fura-2 laddade S5 celler med hjälp av ett ratiometriskt mikrofluorometriskt system. För att undersöka om TRPV1 finns testades ämnena N-(4-hydroxyphenyl)-Arachidonoylamide (AM404) och [5-hydroxyl-1-(4-hydroxy-3-methoxyphenyl)decan-3-one] ([6]-gingerol). För att undersöka om TRPV4 finns användes det TRPV4-specifika ämnet (4alpha-Phorbol 12,13-Didecanoate)

4α–PDD.

De båda TRPV1 agonisterna AM404 och [6]-gingerol inducerade en ökning i [Ca²⁺]_i. Capsaicin som är en klassisk TRPV1 agonist ökade också [Ca²⁺]_i och användes som kontroll. Alla dessa koncentrationsökningar inhiberades av capsazepine, som är en TRPV1- antagonist. 4α–PDD som är en specifik TRPV4 agonist ökade också [Ca²⁺]_i.

Resultaten tyder på att S5 cellerna uttrycker både TRPV1 och TRPV4 kanaler samt att AM404, [6]-gingerol och 4α–PDD är alla substanser med potential att öka insulinfrisättningen från bukspottkörtelns β celler.

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Beurg, Maryline. "Couplage excitation-contraction des cellules musculaires striées : étude des variations transitoires de calcium par imagerie de fura-2". Bordeaux 1, 1995. http://www.theses.fr/1995BOR10530.

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Le couplage excitation-variation transitoire de ca2+ (e-vt) constitue l'etape cle du couplage e-c des muscles squelettiques. A l'aide de la technique d'imagerie du fura-2, nous avons suivi la dynamique et la distribution spatiale de la concentration de calcium intracellulaire pendant le developpement des myotubes de rat, de souris dysgeniques et humains en culture. Les myotubes de rat in vitro presentent temporairement un stade dit quiescent durant lequel ces cellules sont incapables de se contracter alors qu'elles possedent un couplage e-vt de ca2+ fonctionnel. Lors du couplage e-vt, la liberation de calcium du rs semble se faire en deux etapes successives: la premiere serait regulee par le potentiel et la deuxieme semble etre controlee par le calcium (cicr). Au cours du developpement, les myotubes de rat presentent un couplage e-vt de type cardiaque. Ce couplage apparaissant precocement et de facon fugace reste localise aux extremites des cellules. Les myotubes de souris mdg/mdg bien que depourvus de la sous-unite alphal du r-dhp presentent un couplage e-vt de ca2+ de type cardiaque, localise aux extremites des cellules jeunes. Le support moleculaire d'un tel couplage, faisant office de detecteur de potentiel et de canal calcium, n'a pu etre defini, l'entree de calcium n'etant sensible a aucun des inhibiteurs traditionnels des canaux calciques. De par sa localisation ce couplage pourrait avoir un role dans le processus de fusion cellulaire. En culture, les myotubes humains non innerves ne se contractent pas mais possedent toutefois un couplage e-vt de ca2+ fonctionnel de type squelettique. Dans ces cellules, le noyau presente une vt de ca2+ induite par le potentiel plus lente que celle du cytoplasme, ce qui laisse suggerer des mecanismes de controle du calcium different au niveau du noyau. Le calcium possederait non seulement un role primordial dans la contraction mais aussi peut-etre dans la differenciation du muscle

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Lascombe, Marie-Laure. "Le couplage excitation-contraction dans les cellules musculaires striées normales et dysgéniques : étude par imagerie de fluorescence de fura-2". Bordeaux 1, 1992. http://www.theses.fr/1992BOR10519.

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Pour etudier les mecanismes du couplage excitation-contraction dans les cellules musculaires striees normales et dysgeniques (mdg/mdg) nous avons suivi la dynamique et la distributionspatiale des variations de la ca#2#+#i par videomicroscopie de fluorescence et traitement des images. Dans les myotubes normaux, nous avons trouve: a) l'existence, dans une etape de la myogenese, d'un couplage excitation-augmentation de la ca#2#+#i n'induisant pas de contraction; b) sous l'action de l'acetylcholine, la variation calcique est biphasique avec d'abord la liberation de calcium apparemment module par un second messager ou une proteine g. Dans les myotubes de souris mdg/mdg, nous avons constate la presence d'un couplage excitation-augmentation de la ca#2#+#i localise aux extremites des cellules. Le detecteur de voltage semble etre different de celui actuellement connu, le recepteur des dihydropyridines

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Castro, Kraftchenko Joel, i kraf0005@flinders edu au. "STORE OPERATED Ca2+ CHANNELS IN LIVER CELLS: REGULATION BY BILE ACIDS AND A SUB-REGION OF THE ENDOPLASMIC RETICULUM". Flinders University. Medicine, 2008. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20080826.135311.

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Cholestasis is an important liver pathology. During cholestasis bile acids accumulate in the bile canaliculus affecting hepatocyte viability. The actions of bile acids require changes in the release of Ca2+ from intracellular stores and in Ca2+ entry. The target(s) of the Ca2+ entry pathway affected by bile acids is, however, not known. The overall objective of the work described in this thesis was to elucidate the target(s) and mechanism(s) of bile acids-induced modulation of hepatocytes calcium homeostasis. First, it was shown that a 12 h pre-incubation with cholestatic bile acids (to mimic cholestasis conditions) induced the inhibition of Ca2+ entry through store-operated Ca2+ channels (SOCs), while the addition of choleretic bile acids to the incubation medium caused the reversible activation of Ca2+ entry through SOCs. Moreover, it was shown that incubation of liver cells with choleretic bile acids counteracts the inhibition of Ca2+ entry caused by pre-incubation with cholestatic bile acids. Thus, it was concluded that SOCs are the target of bile acids action in liver cells. Surprisingly, despite the effect of choleretic bile acids in activating SOCs, the Ca2+ dye fura-2 failed to detect choleretic bile acid-induced Ca2+ release from intracellular stores in the absence of extracellular Ca2+. However, under the same conditions, when the sub-plasma membrane Ca2+ levels were measured using FFP-18 Ca2+ dye, choleretic bile acid induced a transient increase in FFP-18 fluorescence. This evidence suggested that choleretic bile acids-induced activation of Ca2+ entry through SOCs, involving the release of Ca2+ from a region of the endoplasmic reticulum (ER) located in the vicinity of the plasma membrane.

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Scanlon, Mary. "Cellular mechanism of neutrophil chemotaxis: the role of CA⁺², as viewed with the fluorescent dye, FURA-2, in the polarization of human polymorphonuclear leukocytes following stimulation with the chemoattractant, F-Methionyl-Leucyl-Phenylalanine: a thesis". eScholarship@UMMS, 1987. https://escholarship.umassmed.edu/gsbs_diss/320.

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The mechanism by which a cell translates a spatially oriented, extracellular signal into a change in morphology and behavior is the key to understanding many biological processes. In order to investigate this general phenomenon, I have studied the chemotactic response of human polymorphonuclear leukocytes (PMN's) to f-methionyl-leucyl-phenylalanine (fMLP). Stimulation of PMN's with fMLP produces a plethora of intracellular events, including increases in cytosolic Ca+2. PMN's are also morphologically and behaviorally polarized by stimulation with chemoattractant; the membrane components and cytosolic organelles of polarized PMN's become asymmetrically distributed. Polarization and subsequent orientation of PMN's in the direction of fMLP are steps which precede and are necessary for chemotaxis. I have chosen to examine the role of Ca+2, a ubiquitous second messenger, in the polarization of PMN's to fMLP. To accomplish this goal, Ca+2 has been measured in resting and polarized PMN's, utilizing the intracellular fluorescence of the Ca+2-sensitive dye, fura-2. Initial experiments have revealed a Ca+2-insensitive form of fura-2 associated with PMN's which, if uncorrected, would lead to erroneous measurements of [Ca+2]. I have suggested putative sources for the Ca+2-insensitive fluorescence in PMN's and have presented two methods for accurate calculation of [Ca+2] in spite of the additional component of fluorescence. As measured from the cell-associated fluorescence of fura-2, [Ca+2] increases without a detectable lag upon addition of fMLP to PMN's in suspension. The rise in [Ca+2] is associated with an increase in the percentage of cells which polarize to fMLP. The increases in [Ca+2] and in polarization are both directly related to increases in the concentration of chemoattractant. Inhibition of the rise in [Ca+2], by exposure of the human donor to aspirin or addition of EGTA to isolated cells, results in a concommitant reduction in the percentage of cells which polarize to fMLP. These findings are consistent with the hypothesis that Ca+2 acts as a second messenger in the pathway of transduction of the extracellular signal which results in polarization. However, addition of ionomycin, the Ca+2-selective ionophore, to PMN's did not induce polarization either in the presence or in the absence of fMLP. This result suggests that increases Ca+2, which appear to be necessary for polarization, are locally distributed within the fMLP-stimulated PMN. Examination of the subcellular distribution of Ca+2 using the digital imaging microscope reveals that Ca+2 is not uniformly distributed in the polarized PMN. Cells polarized by stimulation with fMLP often exhibit regional differences in [Ca+2] from front to tail. The magnitude and direction of the intracellular gradient varies among cells and suggests that within individual cells, the heterogeneity of [Ca+2] varies temporally and spatially as the cell chemotaxes. The results of the experiments conducted in this dissertation suggest that Ca+2 plays an important role as second messenger in fMLP-stimulated PMN's. I suggest that the morphological polarity of the chemotactic PMN is dependent upon the establishment and maintenance of an intracellular Ca+2 gradient.

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Westerlund, Johanna. "Pulsatile insulin release from single islets of Langerhans". Doctoral thesis, Uppsala University, Department of Medical Cell Biology, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-494.

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Insulin release from single islets of Langerhans is pulsatile. The secretory activities of the islets in the pancreas are coordinated resulting in plasma insulin oscillations. Nutrients amplitude-regulate the insulin pulses without influencing their frequency. Diabetic patients show an abnormal plasma insulin pattern, but the cause of the disturbance remains to be elucidated. Ithe present thesis the influence of the cytoplasmic calcium concentratio([Ca²⁺]_i) and cell metabolism on pulsatile insulin release was examined in single islets of Langerhans from ob/ob-mice. Glucose stimulation of insulin release involves closure of ATP-sensitive K⁺ channels (K_ATP channels), depolarization, and Ca²⁺ influx in β-cells. In the presence of 11 mM glucose, pulsatile insulin secretion occurs in synchrony with oscillations i[Ca²⁺]_i. When [Ca²⁺]_i is low and stable, e.g. under basal conditions, low amplitude insulin pulses are still observed. When [Ca²⁺]_i is elevated and non-oscillating, e.g. when the β-cells are depolarized by potassium, high amplitude insulin pulses are observed. The frequency of the insulin pulses under these conditions is similar to that observed when [Ca²⁺]_i oscillations are present. By permanently opening or closing the K_ATP channels with diazoxide or tolbutamide, respectively, it was investigated if glucose can modulate pulsatile insulin secretion when it does not influence the channel activity. Under these conditions, [Ca²⁺]_i remained stable whereas the amplitude of the insulin pulses increased with sugar stimulation without change in the frequency. Metabolic inhibition blunted but did not prevent the insulin pulses. The results indicate that oscillations in metabolism can generate pulsatile insulin release when [Ca²⁺]_i is stable. However, under physiological conditions, pulsatile secretion is driven by oscillations in metabolism and [Ca²⁺]_i, acting in synergy.

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Egunlusi, Ayodeji Olatunde. "Novel tricycloundecane derivatives as potential N-methyl-Daspartate receptor and calcium channel inhibitors for neuroprotection". Thesis, University of the Western Cape, 2014. http://hdl.handle.net/11394/3904.

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>Magister Scientiae - MSc
This study focused on the synthesis of a series of novel tricycloundecane derivatives and evaluation of these compounds for neuroprotection using the fluorescent ratiometric calcium assay that indicates the ability of the test compounds to inhibit NMDA receptors and VGCC. The cycloaddition reaction between p-benzoquinone and monomerised dicyclopentadiene yielded tricycloundeca- 4,9-diene-3,6-dione which was used as the base structure and further derivatised. These derivatives were conjugated with benzylamine to form a series of imines and amines. A total of 10 compounds were synthesised for evaluation of inhibition of calcium influx through NMDA receptor channels and voltage-gated calcium channels. The structures were confirmed using NMR, IR and MS. On the proton NMR, the characteristic AB-quartet system was observed in the region of 1-2 ppm for all the compounds and the aromatic moiety was observed between 6.5-7.5 ppm for the novel polycyclic amines. These, with other functional groups, were used to confirm the individual structures

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Liu, Li. "Roles of PMCA Isoforms in Ca²⁺-Homeostasis and Contractility of Bladder Smooth Muscle: Evidence from PMCA Gene-Ablated Mice". Cincinnati, Ohio : University of Cincinnati, 2007. http://rave.ohiolink.edu/etdc/view.cgi?acc_num=ucin1178307168.

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Thesis (Ph.D.)--University of Cincinnati, 2007.
Advisor: Richard J. Paul. Title from electronic thesis title page (viewed Apr. 4, 2009). Keywords: PMCA (human gene symbols; ATP2B); SERCA2 (human gene symbols; ATP2A2); NCX; bladder smooth muscle; Ca²⁺ homeostasis; gene-altered mice. Ca²⁺ waves; Ca²⁺ sparks; Fura-PE3; Fluo-4; Indo-1; multi-photon microscopy. Includes abstract. Includes bibliographical references.

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Ahmed, Meftun. "Oscillatory Ca²⁺ signaling in glucose-stimulated murine pancreatic β-cells : Modulation by amino acids, glucagon, caffeine and ryanodine". Doctoral thesis, Uppsala University, Department of Medical Cell Biology, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-1408.

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Oscillations in cytoplasmic Ca²⁺ concentration ([Ca²⁺]_i) is the key signal in glucose-stimulated β-cells governing pulsatile insulin release. The glucose response of mouse β-cells is often manifested as slow oscillations and rapid transients of [Ca²⁺]_i. In the present study, microfluorometric technique was used to evaluate the role of amino acids, glucagon, ryanodine and caffeine on the generation and maintenance of [Ca²⁺]_i oscillations and transients in individual murine β-cells and isolated mouse pancreatic islets. The amino acids glycine, alanine and arginine, at around their physiological concentrations, transformed the glucose-induced slow oscillations of [Ca²⁺]_i in isolated mouse β-cells into sustained elevation. Increased Ca²⁺ entry promoted the reappearance of the slow [Ca²⁺]_i oscillations. The [Ca²⁺]_i oscillations were more resistant to amino acid transformation in intact islets, supporting the idea that cellular interactions are important for maintaining the oscillatory activity. Individual rat β-cells responded to glucose stimulation with slow [Ca²⁺]_i oscillations due to periodic entry of Ca²⁺ as well as with transients evoked by mobilization of intracellular stores. The [Ca²⁺]_i oscillations in rat β-cells had a slightly lower frequency than those in mouse β-cells and were more easily transformed into sustained elevation in the presence of glucagon or caffeine. The transients of [Ca²⁺]_i were more common in rat than in mouse β-cells and often appeared in synchrony also in cells lacking physical contact. Depolarization enhanced the generation of [Ca²⁺]_i transients. In accordance with the idea that β-cells have functionally active ryanodine receptors, it was found that ryanodine sometimes restored oscillatory activity abolished by caffeine. However, the IP3 receptors are the major Ca²⁺ release channels both in β-cells from rats and mice. Single β-cells from ob/ob mice did not differ from those of lean controls with regard to frequency, amplitudes and half-widths of the slow [Ca²⁺]_i oscillations. Nevertheless, there was an excessive firing of [Ca²⁺]_i transients in the β-cells from the ob/ob mice, which was suppressed by leptin at close to physiological concentrations. The enhanced firing of [Ca²⁺]_i transients in ob/ob mouse β-cells may be due to the absence of leptin and mediated by activation of the phospholipase C signaling pathway.

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Richecoeur, Alexandre M. E. "Stannylated furan-2(5H)-ones in organic synthesis". Thesis, University of Bristol, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390103.

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Ahmed, Meftun. "Oscillatory Ca2+ signaling in glucose-stimulated murine pancreatic β-cells : Modulation by amino acids, glucagon, caffeine and ryanodine". Doctoral thesis, Uppsala universitet, Institutionen för medicinsk cellbiologi, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-1408.

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Oscillations in cytoplasmic Ca2+ concentration ([Ca2+]i) is the key signal in glucose-stimulated β-cells governing pulsatile insulin release. The glucose response of mouse β-cells is often manifested as slow oscillations and rapid transients of [Ca2+] i. In the present study, microfluorometric technique was used to evaluate the role of amino acids, glucagon, ryanodine and caffeine on the generation and maintenance of [Ca2+] i oscillations and transients in individual murine β-cells and isolated mouse pancreatic islets. The amino acids glycine, alanine and arginine, at around their physiological concentrations, transformed the glucose-induced slow oscillations of [Ca2+] i in isolated mouse β-cells into sustained elevation. Increased Ca2+ entry promoted the reappearance of the slow [Ca2+] i oscillations. The [Ca2+] i oscillations were more resistant to amino acid transformation in intact islets, supporting the idea that cellular interactions are important for maintaining the oscillatory activity. Individual rat β-cells responded to glucose stimulation with slow [Ca2+] i oscillations due to periodic entry of Ca2+ as well as with transients evoked by mobilization of intracellular stores. The [Ca2+] i oscillations in rat β-cells had a slightly lower frequency than those in mouse β-cells and were more easily transformed into sustained elevation in the presence of glucagon or caffeine. The transients of [Ca2+] i were more common in rat than in mouse β-cells and often appeared in synchrony also in cells lacking physical contact. Depolarization enhanced the generation of [Ca2+] i transients. In accordance with the idea that β-cells have functionally active ryanodine receptors, it was found that ryanodine sometimes restored oscillatory activity abolished by caffeine. However, the IP3 receptors are the major Ca2+ release channels both in β-cells from rats and mice. Single β-cells from ob/ob mice did not differ from those of lean controls with regard to frequency, amplitudes and half-widths of the slow [Ca2+] i oscillations. Nevertheless, there was an excessive firing of [Ca2+] i transients in the β-cells from the ob/ob mice, which was suppressed by leptin at close to physiological concentrations. The enhanced firing of [Ca2+] i transients in ob/ob mouse β-cells may be due to the absence of leptin and mediated by activation of the phospholipase C signaling pathway.

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Mabon, Ross. "Investigation of the reactions of bis stannyl furan 2(#ETA#) one". Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269910.

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Partlett, N. K. "The synthetic utility of 5-O-hydroxymethyl-(5H)-furan-2-one". Thesis, University of Reading, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233186.

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Carter, Neil B. "Investigations into the reactions of 3,4-bis(tributylstannyl)furan-2(5H)-one". Thesis, University of Reading, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250647.

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Hama, Salih Mariwan Abdulla. "Synthesis of azetidines, γ-lactams, fused furan bispyrrolidines and 2-pyrazolines : towards medical application". Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6838/.

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Azetidines are important class of heterocyclic organic compounds in drug discovery and natural product synthesis. Several natural products and pharmaceuticals are containing azetidine precursors such as, penaresidin and Azelnidipine. Iodine mediated cyclisation of homoallylamines were found to furnish iodoazetidines at 20 °C and further reaction with amine nucelophiles afforded aminoazetidines in high yields. The cyclisation of various homoallylamines which different substitution patterns using molecular iodine to furnish new classes of compounds with interesting biological applications were studied. The iodocyclisation of 3-methyl substituted homoallylamine were found to deliver γ-lactam compound in moderate yield as a mixture of diastereoisomers, the reaction conditions were optimised, and the separation into single diastereoisomers and modification in to pyrrolidine ring were investigated. The tricyclic furan bispyrrolidines were obtained in relatively low yields when 3-phenyl substituted homoallylamines were cyclised using the same strategy. The cyclisation of homoallylhydrazines to deliver pyrazoline compounds in high yield was studied in detail. Finally, the biological activity of some of the synthesised compounds were investigated in zebrafish embryo developmental assays and showed intriguing biological responses. Some of the synthesised compounds were sent to Syngenta and Lilly Company for further investigation.

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Weymouth-Wilson, Alexander Charles. "The photocatalytic addition of alcohols to 5-substituted furan-2(5H)-ones : scope and utility". Thesis, University of Reading, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320550.

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Teixeira, Milena Galdino. "Síntese e avaliação das atividades inseticida e herbicida de derivados da furan-2(5H)-ona". Universidade Federal de Viçosa, 2015. http://www.locus.ufv.br/handle/123456789/8498.

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As ftalidas ou isobenzofuranonas são γ -lactonas fundidas com um anel aromático. As isobenzofuran-1(3H)-onas, e seus análogos correspondentes tetraidro- e hexaidroisobenzofuran-1(3H)-onas, são produtos naturais e possuem variadas atividades biológicas, como: inseticida, herbicida, anti- inflamatória e antifúngica. O presente trabalho teve por objetivo sintetizar novas ftalidas visando avaliar a atividade inseticida e herbicida desses compostos. A rota sintética escolhida teve como material de partida a lactona furan-2(5H)-ona (1). Essa substância foi então submetida à reação de Diels-Alder com o ciclopentadieno, levando a formação dos compostos (3aR,4S,7R,7aS)- e (3aS,4R,7S,7aR)-3a,4,7,7a-tetraidro-4,7-metanoisobenzofuran-1(3H)-ona (2) e (3aS,4S,7R,7aR)- e (3aR,4R,7S,7aS)-3a,4,7,7a-tetraidro-4,7- metanoisobenzofuran-1(3H)-ona (3) com 66,3% e 17,7% de rendimento, respectivamente. Esses compostos foram submetidos às reações de epoxidação, hidrogenação, cloração e bromação, e foram obtidas onze substâncias com rendimentos que variaram de 59 a 98%. Com o epóxido obtido a partir do composto 2 foi realizada à reação de abertura de epóxido em meio ácido, variando-se o álcool empregado, o que deu origem a cinco substâncias em rendimentos que variaram de 46 a 74%. Os compostos sintetizados foram completamente caracterizados, utilizando-se espectroscopia no IV, espectroscopia de RMN de 1 H e de a 13 C, NOEDIFF, técnicas bidimensionais HMBC, HSQC, HETCOR e NOESY, espectrometria de massas, além de em alguns casos cálculos computacionais. As ftalidas sintetizadas tiveram sua atividade inseticida investigada por meio da realização de bioensaios com a lagarta Diaphania hyalinata. Dentre as substâncias avaliadas, os compostos 11a+11b, 11b e 9a+9b foram os mais ativos. Considerando-se a dose de 45,2 mol de substância/g de inseto e um período de 48 horas, estas substâncias causaram, respectivamente, 84,8, 91,3 e 96,3% de mortalidade dos insetos. Esses resultados são melhores que o encontrado para o inseticida padrão utilizado (piperina) que apresentou uma mortalidade de 64,5%. Foi verificada também a seletividade desses inseticidas em favor de organismos não-alvos: a abelha polinizadora e produtora de mel (Tetragonisca angustula) e o inimigo natural (Solenopsis saevissima). Os resultados obtidos mostram que as substâncias 11b e 11a+11b foram seletivas, uma vez que a mortalidade dos organismos benéficos foi inferior à obtida para a praga D. hyalinata. Foi realizada também uma avaliação in vitro do efeito fitotóxico dos compostos sintetizados sobre o crescimento radicular e da parte aérea de plâtulas de pepino (Cucumis sativus), sorgo (Sorghum bicolor), cebola (Allium cepa) e picão preto (Bidens pilosa). Os resultados mostraram que alguns desses compostos são capazes de influenciar significativamente o crescimento dessas plântulas. As lactonas 8, 9a+9b, 11a+11b, 11a, 11b e 18 foram as mais ativas frente a todas as espécies testadas. Esses resultados revelam que as isobenzofuran-1(3H)-onas representam uma boa plataforma estrutural para a descoberta de novos compostos com propriedades fitotóxicas e inseticidas.
Phthalides, also known as isobenzofuranones, are characterized by a bicyclic nucleus derived from the fusion of a γ -lactone with a benzene. Isobenzofuran- 1(3H)-ones, and their corresponding analogs tetrahydro- and hexahydroisobenzofuran-1(3H)-ones are frequently found in naturally occurring substances, and exhibit a broad spectrum of biological activities, such as insecticide, herbicide, antiinflammatory and antifungal agents. This study aimed to synthesize new phthalides to evaluate the insecticidal and herbicide activity such compounds. The synthetic route chosen had the furan-2(5H)-one (1) as the starting material. This substance was then subjected to the Diels-Alder reaction with cyclopentadiene, leading to the formation of compounds (3aR,4S,7R,7aS)- and (3aS,4R,7S,7aR)-3a,4,7,7a-tetrahydro-4,7- methanoisobenzofuran-1(3H)-one (3aR,4R,7S,7aS)-3a,4,7,7a- (2) and (3aS,4S,7R,7aR)- and tetrahydro-4,7-methanoisobenzofuran-1(3H)-one (3) in 66.3% and 17.7 % yield, respectively. These compounds were subjected to epoxidation, hydrogenation, chlorination and bromination reactions and eleven substances were obtained with yields ranging from 59 to 98%. With the epoxide obtained from compound 2 was performed to epoxide opening reaction in the presence of acid, by varying the alcohol employed, which led to the formation of five substances in yields ranging from 46 to 74%. All the compounds prepared were fully characterized by IR spectroscopy, 1 H and 13 C NMR spectroscopy, NOEDIFF, two-dimensional techniques HMBC, HSQC, HETCOR and NOESY, mass spectrometry, and in some cases theorical computation. The synthesized phthalides had their insecticidal activity investigated by performing bioassays with caterpillar Diaphania hyalinata. Among the evaluated substances 11a+11b, 11b and 9a+9b were the most active. Considering the dose of 45.2 mol substance/g of insect and a period of 48 hours, these substances caused 84.8, 91.3 and 96.3% of mortality of insects, respectively. These compounds were more active than the commercial piperine which has presented 64.5% of mortality. It was also verified the selectivity of these insecticides in favor of non-target organisms: a bee pollinating and producing honey (Tetragonisca angustula) and the natural enemy (Solenopsis saevissima). The results showed that the substances 11b and 11a+11b were selective, since the mortality of beneficial organisms was less than that obtained for the pest D. hyalinata. On another bioassay the compounds were evaluated for their capacity to inhibit the radicle and the aerial part growth of Cucumis sativus, Sorghum bicolor, Allium cepa, and Bidens pilosa seedlings. The results showed that some of these compounds are capable of influencing significantly the growth of these seedlings. Lactones 8, 9a+9b, 11a+11b, 11a, 11b, and 18 were the most active against all species tested. These results show that isobenzofuran-1(3H)-ones represent good structural platform for the discovery of new compounds displaying selective insecticide and phytotoxic properties.

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Pizzuti, Lucas. "Síntese de 4-(fur-2-il)- e 4-(tien-2-il)-pirimidinas a partir de β-Alcoxivinil trifluormetil cetonas". Universidade Federal de Santa Maria, 2005. http://repositorio.ufsm.br/handle/1/10401.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
The cyclocondensation of the 1,1,1-trifluoro-4-methoxy-4-(2-heteroaryl)-3-buten-2-ones (heteroaryl = furyl and thienyl) with urea and amidines (acetamidine, benzamidine, guanidine, 1H-pyrazole-1-carboxamidine and 2-methyl-2-thiopseudourea) for synthesis of two 4-(2-heteroaryl)-6-trifluoromethylpyrimidinones and a series of ten 4-(2-heteroaryl)-6-trifluoromethylpyrimidines is reported. The reaction of the 1,1,1-trifluoro-4-methoxy-4-(2-heteroaryl)-3-buten-2-ones with urea was carried out in the presence of boron trifluoride etherate as a catalyst, at 50°C for 20 hours. The reactions of the same substracts with amidines were carried out in the presence of a 1 M solution of sodium hydroxide at r.t.-50°C for 1 hour. Under this conditions, only aromatic pyrimidines were obtained in 48-67%.
Este trabalho relata a síntese e isolamento de duas 4-(2-heteroaril)-6-trifluormetilpirimidinonas e uma série de dez 4-(2-heteroaril)-6-trifluormetilpirimidinas (heteroaril = furil e tienil), a partir da ciclocondensação de 1,1,1-trifluor-4-metoxi-4-(2-heteroaril)-3-buten-2-onas com uréia e amidinas (acetamidina, benzamidina, guanidina, 1Hpirazolil-1-carboxamidina e 2-metil-2-tiopseudouréia). A reação de 1,1,1-trifluor-4-metoxi-4-(2-heteroaril)-3-buten-2-onas com uréia ocorreu na presença de BF3.Et2O como catalisador, à 50°C por 20 horas. As reações dos mesmos substratos com amidinas ocorreu na presença de uma solução 1 M de NaOH à t.a.-50°C por 1 hora. Nestas condições, foram obtidas somente pirimidinas aromáticas com rendimentos entre 48-67%.

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20

Langley, Christopher A. "A combinatorial approach to the chemical synthesis and biological evaluation of 3,4,5-trisubstiituted furan-2(5H)-ones". Thesis, Aston University, 2000. http://publications.aston.ac.uk/10985/.

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Many important natural products contain the furan-2(5H)-one structure. The structure of this molecule lends itself to manipulation using combinatorial techniques due to the presence of more than one site for the attachment of different suhstituents. By developing different reaction schemes at the three sites available for attachment on the furan-2(5H)-one scaffold, combinatorial chemistry techniques can be employed to assemble libraries of novel furan 2(5H)-ones. These libraries can then be entered into various biological screening programmes. This approach will enable a vast diversity or compounds to be examined, in the hope or finding new biologically active Iead structures. The work in this thesis has investigated the potential that combinatorial chemistry has in the quest for new biologically active lead structures based on the furan-2(5H)-one structure. Different reactions were investigated with respect to their suitability for inclusion in a library. Once sets of reactions at the various sites had been established, the viability of these reactions in the assembly of combinatorial libraries was investigated. Purification methods were developed, and the purified products entered into suitable biological screening tests. Results from some of these tests were optimised using structure activity relationships, and the resulting products re-screened. The screening tests performed were for anticancer and antimicrobial activity, cholecystokinin (CCK-B) antagonism and anti-inflammatory activity (in the quest for novel cyclo-oxygenase (COX-2) selective non-steroidal anti-inflammatory drugs). It has been shown that many reactions undergone by the furan-2(5H)-one structure are suitable for the assembly of a combinatorial library. Investigation into the assembly of different libraries has been carried out with initial screening results included. From this work, further investigation into combinatorial library assembly and structure activity relationships of screened reaction products can be undertaken.

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Coelho, Helena Sebastiany. "Síntese e atividade biológica de furan-3-carboxamidas, 3-aminometilenodiidrofuran-2-onas e carbamatos de etila trialometilados". Universidade Federal de Santa Maria, 2007. http://repositorio.ufsm.br/handle/1/4301.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
The present work describes the synthesis of a new series of furan-3-carboxamides and 3-aminomethylenedihydrofuran-2-ones, through the reactions of 3-trichloroacetyl furan or furan-3-carbonyl chloride, and 3-trichloroacetyl-4,5-dihydrofuran respectively, with benzamidine, primary and secondary amines, in good yields (63-98%). The synthesis of furan-3-carboxamides, begins from the aromatization of 3-trichloroacetyl-4,5-dihydrofuran to 3-tricloroacetyl furan followed by the nucleophilic displacement of the trichloromethyl group or the corresponding carboxylic acid chloride by nitrogen-containing compounds. The 3-aminomethylenedihydro-furan-2-ones were obtained, from a simple methodology, in a single reaction step, by the addition reaction of amines to 3-tricloroacetyl-4,5-dihydrofuran, in the same molar quantities. The compounds were evaluated for their in vitro antimicrobial activity against a panel of microorganisms including yeasts, filamentous fungi, bacteria and alga. Some of the furan-3-carboxamides and trihalomethylated ethyl carbamates exhibited significant antimicrobial activity. The in vivo toxicity of a series of aminomethylenedihydrofuran-2-ones against Artemia salina was evaluated. The results exhibited significant activity for the compounds 3-N-2-1-benzyl-piperidin-4-ylethylaminemethylendihydrofuran-2-one and 6-(2-hydroxy-ethyl)-7-oxo-1,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidine-2-carboxylic acid, when compared with controls.
Este trabalho apresenta a síntese de furan-3-carboxamidas e 3-aminometilenodiidrofuran-2-onas, duas séries de compostos obtidos com bons rendimentos (63-98%) e inéditos na literatura. A síntese das furan-3-carboxamidas, iniciou com a aromatização de 3-tricloroacetil-4,5-diidrofurano a 3-tricloroacetil furano seguido por substituição do grupo triclorometil ou do correspondente cloreto de ácido carboxílico por grupos amino substituídos. As 3-aminometilenodiidrofuran-2-onas foram obtidas, através de uma metodologia simples, em um único passo reacional, a partir da reação entre aminas e 3-tricloroacetil-4,5-diidrofurano em quantidades equimolares. Os compostos si ntetizados foram avaliados para atividade antimicrobiana in vitro frente a um grupo de microrganismos incluindo fungos leveduriformes, fungos filamentosos, bactérias e uma espécie de alga. Alguns furan-3-carboxamidas e carbamatos de etila derivados de enaminonas trialometiladas exibiram significante atividade antimicrobiana. A toxicidade in vivo, foi avaliada para uma série de aminometilenodiidrofuran-2-onas frente à Artemia salina. Os resultados evidenciaram significativa atividade citotóxica para os compostos 3-N-2-1-benzilpiperidin-4-iletilaminometilenodiidrofuran-2-ona e ácido-6-(2-hidroxi-etil)-7-oxo-1,7-diidro-[1,2,4]triazolo[1,5-a]pirimidina-2-carboxílico, quando comparados aos padrões.

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22

Dussert, Anne-Sophie. "Synthèse et étude biologique de 5H-furan-2-ones spiranniques : mise au point d'une voie d'accès à des 5,6-dihydro-2h-pyran-2-ones fonctionnalisées". Lyon 1, 1993. http://www.theses.fr/1993LYO1T124.

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CHEN, WEIWEN. "Le recepteur de la cholecystokinine couple a la mobilisation du calcium intracellulaire : etude sur des cellules isolees d'acini pancreatiques et de muqueuses gastrique de rat". Paris 7, 1988. http://www.theses.fr/1988PA077035.

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LIAO, LIANG. "Synthese de furan-2-ones et pyran-2-ones naturelles d'interet biologique : cerpegine, yangonine, hispidine et leurs analogues par voie classique ou par activation micro-onde". Caen, 1999. http://www.theses.fr/1999CAEN2021.

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De nouvelles furo3,4-cpyridine-3,4(1h, 5h)-diones et la cerpegine sont synthetisees a partir des -cetols et les reactifs commerciaux catalysees par base en un seul recipient avec de bons rendements globaux. Ce procede original fournis une voie commande d'acces aux derives furo3,4-cpyridine-3,4(1h, 5h)-diones 1,1,5-trisubstitues. De nouveaux acides 2-oxo-4-(aryl-vinyl)-2,5-dihydrofuran-3-carboxyliques et de nouveaux 4-(aryl-vinyl)-2-oxo-2,5-dihydrofuran-3-carboxylates d'ethyles sont prepares en presence de base avec de bons rendements sous micro-ondes. Les voies commandes sous micro-onde en presence de base d'acces a nouveaux 3-aryl-2-imino-5h-furanes, aux 3-aryl-2-oxo-5h-furanes, aux 2-4-(aryl-vinyl)-3-cyano-5h-furan-2-ylidene-malononitriles, et aux (5h)-furan-2-ones-3-fonctionnees soufrees sont realisees. L'elucidation structurale des 3-aryl-2-imino-2,5-dihydrofuranes est presentee. Les syntheses de la yangonine, l'hispidine et leurs derives ont ete realisees a partir des reactifs commerciaux donc une etape a ete effectuee sous micro-ondes avec une reduction considerable du temps de reaction. Basant sur les 4-hydroxy-pyran-2-ones preparees, de nouvelle(s) 6-(aryl-vinyl)- et 6-methyl-4-hydroxy-3-(phenylthio)-pyran-2-one(s) sont preparees comme inhibiteurs potentiels de la protease du vih-1. De nouveaux composes sont susceptibles d'activite biologique surtout les 4-hydroxy-3-(phenylthio)-pyran-2-one(s) 6-substitues qui sont susceptibles d'antivirale ou d'anti-vih.

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25

Wang, Yu-Pu Ph D. Massachusetts Institute of Technology. "I. [2 +2] Cycloaddition and benzannulation of 2-iodoynamides and application to the construction of highly substituted indoles : II. Synthesis of furo[2,3-g]thieno[2,3-e]indole via a benzannulation strategy". Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/101556.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemistry, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references.
The synthesis and reactions of 2-iodoynamides were investigated. 2-Iodoynamides undergo efficient and regioselective [2 + 2] cycloaddition with ketene to produce cyclobutenones that are useful synthetic building blocks. Reaction of 2-iodoynamides and vinylketenes generated in situ from cyclobutenones proceeds via a pericyclic cascade mechanism to produce highly substituted 2-iodoanilines. Tandem strategies for the synthesis of highly substituted indoles involving this benzannulation reaction were investigated. In addition, the synthesis of furo[2,3-g]thieno[2,3- e]indole, a new tetracyclic aromatic compound, was achieved via a strategy based on benzannulation with ynamides.
by Yu-Pu Wang.
Ph. D.

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26

Mauz, Tobias. "4-Hydrazono-1,3-oxazolidin-2-one 1,3,4-Oxadiazin-2-one und Furo[3,4-d]-pyrimidin-2,4,5-trione als Leitstrukturen neuer antimikrobieller Wirkstoffe Synthese, Analytik und Bestimmung der biologischen Aktivität /". [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=971369089.

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27

Perry, Philip J. "Synthesis and biological evaluation of novel cytotoxic heterocylic compounds : furo[2,3-b]naphthoquinones and 2-aryl-4H-3,1-benzoxazin-4-ones". Thesis, De Montfort University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391202.

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28

Langle, Sandrine. "Synthèse et réactivité de systèmes insaturés dihalogénés : applications en synthèse organique". Tours, 2004. http://www.theses.fr/2004TOUR4028.

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L'étude de la réactivité régio- et stéréosélective du bromure de bromobenzyle nous a permis de synthétiser des motifs styréniques métallés par un bras espaceur de 1 à 3 atomes de carbone ainsi que des motifs bis-aryles en présence de sels de palladuim (catalyse de type Stille ou Suzuki). La synthèse régio- et stéréosélective d'acides et dérivés insaturés β,γ- ou α,β- dihalogénés équivalents à des systèmes tris-électrophiles nous a conduit à étudier la réactivité de ces synthons. L'étude de la réactivité par catalyse palladiées d'acides insaturés β,γ-dihalogénés à conduit à la formation d'acide pyrrol-3-yl acétiques substitués, en une seule étape, selon une quadruple séquence. Ces acides ont permis de former des motifs 5H-furan-2-ones substitués en position 4, par cyclisation intramoléculaire puis couplages palladiés. Une série de différentes catalyses palladiées régio- et stéréosélective sur des acides insaturés α,β-dihalogénés, a permis d'obtenir des oléfines tri-substituées, notamment des précurseurs de dérivés du Naproxène ayant potentiellement des applications pharmaceutiques intéressantes et des motifs 3-alkylidène-4-halogéno-3H-furan-2-ones
The study of the regio- and stereo selective reactivity of the bromobenzyl bromide allowed us to synthesize styrenic compounds metaled with a space arm of 1 or 3 atoms of carbon and bi-arly compounds palladuim salts(Stille or Suzuki cross coupling). The selective synthesis of insaturated acids and esters β,γ ou α,β-dihalogenated equivalents with tris-electrophils systems led us to study the reactivity of these compounds. The study of the reactivity of insaturated acids β,γ-dihalogenated with palladuim cross coupling led to the formation of substituted pyrrol-3-yl acetics acids in one stage according to a triple sequence. These acids also made it possible to form 4-substituted pyrrol-3-yl acetics acids in one stage according to a triple sequence. These acids also made it possible to form 4-substituted-5H-furan-2-ones by intramolecular cyclisation and then cross coupling. A series of different selectivity palladuim cross coupling on insaturated acids α,β-dihalogenated allowed to obtain trisubstituted olefins, in particular precursors of derived from Naproxen having potentially interesting pharmaceuticals applications and 3-alkylidene-4-halogeno-3H-furan-2-ones

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29

Lord, Elin. "Olfactory discrimination of aliphatic 2-ketones and 1-alcohols in South African fur seals (Arctocephalus pusillus pusillus)". Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-18932.

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Odor discrimination ability was tested in four female South African fur seals (Arctocephalus pusillus pusillus) using a food-rewarded two-choice instrumental conditioning paradigm. The seals’ ability to distinguish between members of homologous series of aliphatic ketones (2-butanone to 2-heptanone) and alcohols (1-butanol to 1-heptanol) was assessed. The results showed that three out of four seals successfully discriminated between all of their stimulus combinations in both classes of odorants. One seal succeeded to reach the discrimination criterion with all 2-ketones but failed with all 1-alcohols. No significant correlation between odor discrimination performance and structural similarity of the odorants in terms of differences in carbon chain length was found in either of the two chemical classes. Furthermore, it was found that the 2-ketones were significantly better discriminated than the 1-alcohols. The fact that both classes of odorants are known to be present in the natural environment of seals provides a possible explanation as to why most of the seals were able to successfully discriminate between them. The results of the present study support the notion that the sense of smell may play an important role in behavioral contexts such as social communication, foraging and reproductive behavior of fur seals.

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30

Vaitiulionytė, Diana. "Furo[2,3-d]pirimidinų sintezė ir savybės". Master's thesis, Lithuanian Academic Libraries Network (LABT), 2006. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2006~D_20060613_174528-81935.

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We report herein on the results of N- and O-alkylation of 5-cyano-2-methylsulfanyl-4(3H)- pyrimidinone with 4-substituted ω-bromoacetophenones. Synthesized N-(phenacyl)-4- pyrimidinones and 4-(phenacyloxy)pyrimidines with suitable substituents in pyrimidine ring are versatile synthons for the preparation of fused pyrimidine heterocycles. Chemical properties of new furo[2,3-d]pyrimidines were investigated. The structure of synthesized compounds was confirmed by data of 1H NMR, IR and UV spectra.

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31

Tran, Luc Sy. "Étude de la formation de polluants lors de la combustion de carburants oxygénés". Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0171/document.

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L'épuisement des réserves pétrolières et l'augmentation de la concentration du gaz à effet de serre CO2 sont les deux principaux problèmes connus liés à l'utilisation des carburants fossiles. Les biocarburants apparaissent comme un des moyens permettant à la fois une diminution de la dépendance au pétrole et une réduction de l'impact néfaste des moteurs automobiles sur l'environnement. Les biocarburants sont en effet considérés comme une source d'énergie renouvelable. L'objectif de cette thèse était de développer et valider les modèles cinétiques de combustion des composés oxygénés de biocarburants : l'éthanol, les biocarburants de deuxième-génération des familles du furane (furane, 2-méthylfurane, 2,5-diméthylfurane), du tétrahydrofurane (tétrahydrofurane, 2-méthyltétrahydrofurane) et le tétrahydropyrane, en utilisant les nouvelles données obtenues en flamme laminaire pré-mélangée à basse pression. De 20 à 60 produits ont été quantifiés par chromatographie en phase gazeuse et identifiés par couplage avec la spectrométrie de masse. Les résultats obtenus ont ensuite été utilisés pour analyser les voies de consommation des réactifs et de formation des produits, surtout pour les polluants, dans le but de mieux comprendre la chimie de la combustion de ces biocarburants. Ce rapport comprend 5 chapitres et une conclusion. Le premier chapitre présente une revue bibliographique des travaux antérieurs sur l'oxydation de l'éthanol et des éthers cycliques. Dans le second chapitre, le dispositif expérimental est décrit, en détaillant en particulier les nouveaux développements. Enfin les chapitres 3, 4, 5 présentent les résultats de l'étude de la combustion des composés étudiés
The decrease of petroleum reserves and the increase of concentration of greenhouse gas CO2 are the two major known problems related to the use of fossil fuels. Bio-fuels appear as a means allowing a decrease of the dependence on fossil fuels and a reduction of the harmful impact of engine on the environment. Bio fuels are considered as a source of renewable energy. The aim of this thesis was to develop and validate experimentally the high temperature kinetic models for the combustion of oxygenated compounds of bio-fuels: ethanol, second-generation bio-fuels of families of furan (furan, 2-methylfuran, 2,5-dimethylfuran), of tetrahydrofuran (tetrahydrofuran, 2 methyltetrahydrofuran), and tetrahydropyran, using new data obtained in laminar premixed low-pressure flame. About 20-60 products were quantified by gas chromatography and identified using mass spectrometry. The results obtained were then used to analyze the consumption pathways of fuels and the formation pathways of products, especially for pollutants, in order to better understand the combustion chemistry of these bio-fuels. This thesis report includes 5 chapters and a conclusion. The first chapter presents a review of the major works already published in the literature for the oxidation of ethanol and cyclic ethers. In the second chapter, the experimental setup of laminar premixed flame with the analytical techniques is described, detailing in particular new developments. Eventually, chapters 3, 4, 5 present the experimental and modeling results of the study of the combustion chemistry of the compounds studied

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WEBER, M. ELISABETH. "Transporteurs de pyrimidines chez saccharomyces cerevisiae : sequence de deux genes et prediction de structure des proteines correspondantes". Université Louis Pasteur (Strasbourg) (1971-2008), 1987. http://www.theses.fr/1987STR13197.

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Rameesdeen, Sabra Banu. "Investigation of the ketonization reaction of renewable acids and esters". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2022. http://amslaurea.unibo.it/25424/.

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Ketonization is a promising reaction for the upgrading of bio oils produced from biomass and it is used for the preparation of highly valuable asymmetrical ketones such as di-hydrocalchone (HC) and acetyl furan (Ac-Fur). But, they are produced in the liquid-phase with poorly sustainable processes, e.g. Friedel-Crafts acylations (Ac-Fur) and tandem acylation/alkylation (HC) with homogeneous Lewis acid catalysts or oxidations with organic peroxides and excess MnO2 (HC) or H2O2 and inorganic homogeneous catalysts. The development of an alternative gas-phase process to produce HC and Et-Fur by means of cross-ketonization is highly desirable because it would avoid the issues of traditional methods. Moreover, most reactants required for the ketonization process could be prepared from renewable resources. This thesis was dedicated to the study of the cross-ketonization between ethyl benzoate (EB) and ethyl-3-phenylpropionate (EPP) and between ethyl acetate (EtOAc) and ethyl-2-furoate (Et-Fur) to synthetize HC and 2-Ac-Fur respectively. Ketonization of EPP with EB was carried out over different metal oxides (namely ZrO2, La2O3, CeO2) and it was found that ZrO2 was the best catalyst, probably due to its amphoteric properties. Over this material, the formation of HC was maximized by a large excess of EB (EB/EPP= 9) and by a high reaction temperature (350 °C); the effect of water co-feeding was also evaluated in the attempt of maximize HC yield by hydrolyzing EB in situ and producing the more reactive BA, but it was found that instead water reduces catalyst activity. Similar conclusions were drawn investigating the ketonization of Et-Fur with EtOAc over ZrO2. In conclusion, HC was obtained with 80% selectivity at 77% EPP conversion at 350 °C, with 1 second and with a EB/EPP molar ratio = 9, while Ac-Fur was obtained with 82% selectivity at 82% Et-Fur conversion in the same conditions but with a lower EtOAc/Et-Fur molar ratio of 4.

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Silva, José Atalvanio da. "Estudo Cristaloquimico de dois derivados Naftoquinônicos pela aplicação de difração de raios X: 4,5-Diidro-6,6-Dimetil-6h-2-(3 -Metilfenil)-Furan[B-4,3] Nafto[1,2-D] Imidazol (Nppn3171) E 4,5-Diidro-6,6-Dimetil 6h-2 (Fenil)-Piran [B-4,3]-Nafto[1,2-D]-Imidazol (Nppn3073)". Universidade Federal de Alagoas, 2010. http://repositorio.ufal.br/handle/riufal/1101.

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This study aimed to perform the collection of the intensities of diffracted X-ray beam, solving the crystal structures, refine the collected data to compare the molecular structures obtained, the proposals submitted by the group of the Pesquisa em Produtos Naturais (NPPN) da Universidade Federal do Rio de Janeiro (UFRJ) and to characterize the crystal packing identifying possible interactions of hydrogen. In Chapter I, has an introduction to organic compounds as potential pharmaceutical and distribution of Chagas disease in the world and in Brazil, highlighting data from the State of Alagoas. In Chapter II presents a theoretical foundation of X-rays as well as the concept of crystal, followed by Chapter III, using materials and methods and in Chapter IV, are the results and discussions. The compounds studied in this work were 4,5-dihydro-6 ,6-dimethyl-6H-2-(3'-methylphenyl)-furan [B-4,3] naphtha [1,2-D] Imidazole (NPPN3171) and 4,5-dihydro-6 ,6-dimethyl-6H-2 (phenyl)-piran [B-4, 3]-naphtha [1,2-D]-imidazole (NPPN3037). The single crystal samples were courtesy of NPPN/ UFRJ, in the person of Professor Antonio Ventura Pinto. The crystals were selected, glued on glass fibers and set the goniometric head. Data were collected using an automatic diffractometer Kappa CCD. The structures were solved using the software package contained in the WinGX v1.70.01. The compound NPPN3171crystallizes in monoclinic crystal system, space group P21/c with the following parameters a = 9.2587(2)Å, b = 9.8049(4)Å, c = 19.3851 (7) Å; β = 101.365 (2) and Z = 4 molecules /cell. Were collected 3506 unique reflections with use of automatic KappaCCD diffractometer using the Kα radiation of molybdenum ( = 0.71073 Å) monochromatized by a graphite crystal. Were considered 2382 observed reflections giving a final discrepancy index (Robs) of 0.0555. In the crystal packing observed the presence of classical intermolecular hydrogen bonds. To compound NPP3073 the linear parameters were obtained: a = 9.0547(2)Å, b = 10.5956(5)Å, c = 18.7071(10) Å; β = 102.467º (3); crystal system monoclinic space group P21/c and Z = 4 molecules/unit cell. The 2381 observed reflections gave a Robs = 0.1502 reflecting the low quality of data as seen in Rint = 0.1179. Analyzing the molecular structure is observed the presence of a secondary intramolecular interaction (C - H... O)
Conselho Nacional de Desenvolvimento Científico e Tecnológico
Este trabalho teve como objetivos realizar a coleta das intensidades dos feixes de raios X difratados, resolver as estruturas cristalinas, refinar os dados coletados, comparar as estruturas moleculares obtidas, com as propostas fornecidas pelo grupo do Núcleo de Pesquisas de Produtos Naturais (NPPN), da Universidade Federal do Rio de Janeiro (UFRJ) e caracterizar o empacotamento cristalino identificando as possíveis interações de hidrogênio. No capítulo I, tem-se uma introdução sobre os compostos orgânicos como candidatos á fármacos e a distribuição da doença de Chagas no mundo e no Brasil, destacando dados do Estado de Alagoas. No capítulo II, apresenta-se uma fundamentação teórica sobre raios X bem como o conceito de cristal, seguido do capítulo III, com materiais e métodos e no capítulo IV, têm-se os resultados e as discussões dos mesmos. Os compostos estudados neste trabalho foram: 4,5-diidro-6,6-dimetil-6H-2-(3 -metilfenil)-furan[B-4,3] nafto[1,2-D] imidazol (NPPN3171) e 4,5-diidro-6,6-dimetil-6H-2 (fenil)-piran [B-4,3]-nafto[1,2-D]-imidazol (NPPN3037). As amostras monocristalinas foram gentilmente cedidas pelo NPPN da UFRJ, na pessoa do professor Antonio Ventura Pinto. Os cristais foram selecionados, colados em fibra de vidro e fixados na cabeça goniométrica. Os dados foram coletados usando-se um difratômetro automático Kappa CCD. As estruturas foram resolvidas utilizando-se o pacote de programas contido no WinGX v1.70.01. O composto NPPN3171 cristaliza no sistema cristalino monoclínico, grupo espacial P21/c com os seguintes parâmetros a = 9,2587(2)Å, b = 9,8049(4)Å, c = 19,3851(7)Å; β = 101,365o(2) e Z = 4 moléculas/cela. Foram coletadas 3506 reflexões únicas com uso do Difratômetro automático KappaCCD e utilizando a radiação Kα do molibidênio (0,71073Å) monocromatizada por um cristal de grafite. Foram consideradas 2382 reflexões observadas fornecendo um índice de discordância final, (Robs) de 0,0555. No empacotamento cristalino verificou-se a presença de ligações de hidrogênio intermoleculares clássicas. Para o composto NPP3073 os parâmetros lineares obtidos foram: a = 9,0547(2)Å, b = 10,5956(5)Å, c = 18,7071(10)Å; β = 102,467o(3); sistema cristalino monoclínico com grupo espacial P21/c e Z = 4 moléculas/cela unitária. As 2381 reflexões observadas forneceram um Robs = 0,1502 refletindo a baixa qualidade dos dados como verificado no Rint = 0,1179. Analisando a estrutura molecular observa-se a presença de uma interação intramolecular secundária (C H...O)

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Thibault, Charles. "Utilisation de la chimie ''click'' Diels-Alder pour la construction d'hétérocycles oxygénés bioactifs; synthèse d'anhydrides maléiques, de cadiolides, de furo[2,3-b]chromones et découverte inusitée du réarrangement des 3-acyl-2-alkoxyfuranes". Doctoral thesis, Université Laval, 2018. http://hdl.handle.net/20.500.11794/35274.

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Les travaux présentés dans cette thèse concernent l'utilisation de la chimie ''click'' Diels-Alder pour la construction d'hétérocycles oxygénés bioactifs. Dans un premier temps, une nouvelle méthodologie de synthèse versatile menant à des anhydrides maléiques disubstitués est illustrée par la synthèse de l'anhydride chaetomélique A (2.31a, inhibiteur nanomolaire de la FTase) ainsi que la synthèse d'un agent inducteur de la germination (1.26) et d'un nouveau bis-anhydride (1.27) utilisé comme agent de réticulation pour la fixation de cellules ou de tissus. En débutant avec des alcynes commercialement disponibles ou facilement préparables, ces cibles sont assemblées en deux étapes par chimie "click " oxazole-alcyne cycloaddition-cycloréversion suivi par une oxyfonctionnalisation des furanes obtenus. Ensuite, une méthode de synthèse efficace, conciseet modulaire des cadiolides A, B et D est rapportée. Les étapes importantes comportent : (i) l'assemblage du motif β-aryl--benzoyl-buténolide en un seul pot via un tandem Diels-Alder cycloaddition-cycloréversion (oxazole-ynone) régiocontrolé de type "click-unclick"suivi parune hydrolyse du 2-alkoxyfuraneet (ii) une condensation de type Knoevenagel sans groupement protecteur permettant l'obtention rapide des cadiolides A, B et D à partir d'un même précurseur. Par la suite, la découverte inusitée du réarrangement des 3-acyl-2-alkoxyfuranes en furan-3-carboxylate d'alkyle estabordée. Cette transformation, une fois optimisée, permet l'obtention de 13 furan-3-carboxylates d'éthyle. De plus, elle est utilisée comme étape clé dans la synthèse du pumiloxyde aldéhyde, un labdane furfural rare isolé de Tarreanthus africanus, un arbre de la famille des méliacées utilisé au Cameroun pour traiter les vers intestinaux. Finalement, les derniers travaux présentés concernent la synthèse defuro[2,3-b]chromones par tandem Diels-Alder rétro Diels-Alder / addition-élimination oxa-Michael. Cette transformation permet la préparation de cinqfuro[2,3-b]chromones substituées en position C-3. Le potentiel remarquable de cette réaction est démontrée par la première synthèse du bothriofurane A, un produit naturel isoléde Bothriocline laxa. Bien que d'autres groupes de recherche se sont intéressés à la synthèse de ce type de composé, nos travaux constituent le premier exemple de synthèse d'une furo[2,3-b]chromone d'origine naturelle.
This work concerns the use of Diels-Alder ''click'' chemistry for the construction of biologically active oxygen containing heterocycles. First of all, aversatile pathway to substituted maleic anhydrides is illustrated by the synthesis of the nanomolar FTase inhibitor chaetomellic anhydride A(2.31a), a germination promoter(1.26), and a novel bis-anhydride (1.27) cross-linking reagent for cell or tissue fixation. Starting from commercial or easily prepared alkynes, these targets were assembled in two steps by click-unclick oxazole-alkyne cycloaddition-cycloreversion and furan oxyfunctionalization. Secondly, a concise, modular and efficient synthesis of cadiolides A, B, and Dis reported. Prominent steps include : (i) one-pot assembly of a key β-aryl--benzoylbutenolide building block by regiocontrolled "click-unclick"oxazole-ynone Diels-Alder cycloaddition-cycloreversion and ensuing 2-alkoxyfuran hydrolysis, and (ii) a protecting group-free vinylogous Knoevenagel condensation enabling rapid access to cadiolides A, B and D from a common precursor. Then, the unexpected discovery of the ring-degenerate rearrangement of 3-acyl-2-alkoxyfurans to 2-substituted 3-carboalkoxyfurans is described. This transformation, once optimized, enabled the rearrangement of 13 different substrates. The scaffolding power of this chemistry is demonstrated by the first synthesis of pumiloxide aldehyde, a rare labdane furfural isolated from Turreanthus africanus, a cameroonian medicinal treeused to treat intestinal worms. Finally, the synthesis of furo[2,3-b]chromones by a Diels-Alder retro Diels-Alder / oxa-Michael addition-elimination tandem is discussed. This new methodology gives access to 5 different 3-substituted furo[2,3-b]chromones. The remarkable service ability of this transformation is highlighted by the first synthesis of bothriofuran A, a natural product isolated from Bothriocline laxa. Even though many research groups demonstrateinterest in the synthesis of suchcompounds, our work represents the first exemple of a natural furo[2,3-b]chromone synthesis.

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Fernandez, Anne-Marie. "Préparation de γ-butyrolactones γ-alkylées optiquement pures à partir de l'acide L-tartrique. Application à la synthèse totale de la L-bioptérine". Rouen, 1996. http://www.theses.fr/1996ROUES025.

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Une nouvelle méthode pour la préparation de gamma-butyrolactones optiquement pures est proposée. Une stratégie de synthèse donnant accès à deux types de chirons carbonylés (cétones et aldéhyde) a permis le développement de deux réactions hautement stéréosélectives créant ainsi un troisième centre stéréogénique : la réduction des cétones, (2R, 3R)-2,3-dipivaloxy-4-oxo alcanoates de méthyle par le borohydure de sodium dans le méthanol mène aux alcools correspondants (4R), avec des ee>98%, précurseurs des (2R,3S,4R)-2,3-dipivaloxy-4-alkylbutyrolactones. L'addition d'organomagnésiens sur l'aldéhyde (2R,3R)-4-oxo-2,3-dipivaloxy butanoate de méthyle conduit de façon spontanée aux (2R,3S,4S)-2,3-dipivaloxy-4-alkylbutyrolactones avec des ee>98%, épimères des précédentes. Les étapes de lactonisation et de déprotection ont donné accès aux (2R,3S,4R) et (2R,3S,4S)-2,3-dihydroxy-4-alkylbutyrolactones optiquement pures. Certaines de ces lactones ont permis les synthèses formelles de quatre produits naturels : (3R, 4R)-quercus lactone, (-)-avénaciolide, (+)dodécanolactone, (+)-tétrahydrocérulénine enfin, une nouvelle synthèse totale de la L-bioptérine, important composé intervenant comme cofacteur d'enzymes dans de nombreuses réactions biologiques, est effectuée à partir de l'acide L-tartrique via le 5-déoxy-l-arabinose issu de la (2R,3S,4S)-2-3-dihydroxy-4-méthylbutyrolactone.

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Schröder, Christian. "Die Haftung fur Verstosse gegen Privacy Policies und Codes of Conduct nach US-amerikanischem und deutschem Recht : Zugleich ein beitrag zur Rechtsnatur von Datenschutzerklärungen, Verhaltensregeln gem, [paragraph] 38a BDSG und Unternehmensregelungen gem. [paragraph] 4c Abs. 2 BDSG /". Baden-Baden : Nomos, 2007. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=016138110&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

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Chi, Hung Nguyen. "Synthèse et étude de nouveaux analogues tetracycliques et tricycliques des ellipticines et aza-9 ellipticines". Paris 11, 1985. http://www.theses.fr/1985PA112290.

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La présente thèse concerne la synthèse de nouveaux analogues tétracycliques et tricycliques des Ellipticines et aza-9 Ellipticines, ainsi que l'étude de L'étude de leurs propriétés biologiques. L’étude de la lithiation des furo-et pyrrolo [3,2-c] pyridines présentée dans le premier chapitre montre que l'échange avec le ter. Butyl lithium s'effectue sur le sommet 2 de ces hétérocycles. Cela permet d'accéder à divers dérivés fonctionnalisés sur leur sommet 2 à partir desquels nous avons pu accéder d'une part à des pyrido [4,3-b] benzo [f] indoles et d'autre part à des pyrido [3',4': 4,5] pyrrolo [3,2-c] pyridines fonctionnalisés sur leur sommet 1. En particulier l'atome de chlore sur cette position a été substitué par diverses chaînes polyaminées (Chapitres II et III). La mise au point d'une méthode générale d'accès aux hydroxy- 4 (et amino-4) alkyl-5 -1H-pyridones-2 (Chapitre IV) a permis par ailleurs d'élaborer une seconde synthèse, plus générale et moins laborieuse, des pyrido [3',4': 4,5] pyrrolo [3,2-c] pyridines déjà mentionnées (Chapitre V). Dans la partie confidentielle de cette thèse (Chapitre VI), une voie d'accès à d'autres analogues des Ellipticines a été mise au point. Parmi les composés obtenus et notamment parmi les dérivés des pyridopyrrolopyridines substituées en 1 par une chaîne polyaminée, plusieurs manifestent des propriétes antitumorales dignes d'intérêt (Chapitre VII)
This work concerns the synthesis of new tetracyclic and tricyclic analogues of Ellipticines and 9-aza Ellipticines. The lithiation of furo- and pyrrolo [3,2-c] pyridines and subsequent condensation of the lithiated species with various electrophiles leads to 2-functionnalized derivatives of these heterocycles. Starting from the newly obtained intermediates, pyrido (4,3-b] benzo [f] indole and pyrida (3',4' : 4,5] pyrrolo ,[3,2-c] pyridine 1 -Chloro derivatives have been synthesized by multistep sequences (Chapters I,II and III). In chapter IV, a general route to 4-hydroxy (and 4-amino) 5-alkyl -1H- 2-Pyridones is described. Starting from 4-hydroxy 5- methyl -1H- 2-Pyridone, pyrido [3',4' : 4,5 ]- pyrrolo [3,2-c] pyridines have then been obtained by a second route which is more general and convenient that the preceding one (Chapter V). Between various pyridopyrrolopyridines which have a dialkylaminoalkylamino side chain at their 1-position, several have shown interesting antitumor properties

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Pflieger, Dominique. "Antiappetants pour insectes phytophages : synthese d'analogues de l'azadirachtine et de la bisabolangelone". Université Louis Pasteur (Strasbourg) (1971-2008), 1988. http://www.theses.fr/1988STR13149.

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Jacquelin, Jean-Marie. "Fonctionnalisation par métallation d'amino et d'hydroxy quinoléines : applications à la synthèse de furo quinoléines". Rouen, 1987. http://www.theses.fr/1987ROUES033.

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L'amino-2 quinoléine est fonctionnalisée par métallation en position 3. Les amino-3 et -4 quinoléines ont également été métallées respectivement sur les sommets 2 et 8 mais n'ont pu être fonctionnalisées par des électrophiles carbonés. Les hydroxy-2, -3 et -4 quinoléines masquées sous forme de carbamates sont lithiés régiosélectivement sur les carbones 3, 4 et 3 respectivement. Les dérivés ortho substitués préparés par réaction d'aldéhydes sur les intermédiaires lithiés sont utilisés pour la synthèse de furo-quinoléines

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Azevedo, Mariangela Burgos Martins de. "Synthèse énantiosélective de (gamma)-butyrolactones : ()-méthylénolactocine, (-)-acide protolichestérinique, (-)-blastmycinolactol, (+)-blastmycinone, (-)-NFX-2 et (+)-antimycinone". Université Joseph Fourier (Grenoble ; 1971-2015), 1995. http://www.theses.fr/1995GRE10116.

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La cycloaddition du dichlorocetene avec des éthers d'enols chiraux conduit à des cyclobutanones fonctionnalisées avec une diastéréosélectivité élevée. Cette réaction est basée sur la différenciation des faces de la double liaison de l'oléfine chirale. Des intermédiaires de pureté enantiomerique élevée, comme les gamma-butyrolactones, sont obtenus à partir des cycloadduits. Au cours de ce travail, nous avons effectué les premières synthèses enantioselectives des produits naturels suivants: la (moins)-methylenolactocine et l'(moins)-acide protolichesterinique. Ces alpha-méthylène-gamma-butyrolactones possèdent des propriétés antibiotiques et antitumorales importantes. Dans cette partie du travail une réaction d'alpha-méthylation de gamma-butyrolactones a été mise au point. Dans un deuxième temps, nous avons effectué la synthèse asymétrique d'un certain nombre de gamma-butyrolactones beta-oxygénées: (moins)-blastmycinolactol, (plus)-blastmycinone, (moins)-nfx-deux et (plus)-antimycinone, composés issus des antibiotiques antimicynones a(trois) et a(un) respectivement

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Geibel, Uta. "Entwicklung und Validierung eines neuen Schnellmessverfahrens für Adrenalin im Blutserum". Doctoral thesis, 2017. http://hdl.handle.net/11858/00-1735-0000-0023-3F20-0.

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TSAI, WEIN-SHIANG, i 蔡文翔. "Fura-2 loading and its use as an indicator of cytosolic free calcium in cardiomyocytes". Thesis, 1992. http://ndltd.ncl.edu.tw/handle/55905878881177513301.

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碩士
輔仁大學
生物學研究所
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Fura-2乃目前常用來測量細胞內自由態鈣進離子的一種螢光劑。本研究乃探fura-2在新生大白鼠心肌細胞內之分布情形。結果顯示隨著處理時間的增加，細胞內fura-2螢光強度亦隨之增強。但fura-2在細胞內之分布並不均勻：細胞質，細胞核、粒線體，溶體內均有fura-2。而細胞在fura-2 AM 處理後再於37℃下靜置10-30 分鐘則有利於fura-2 AM 之解。但細胞先在4℃ 預冷10分鐘後再和fura-2 AM 在37℃一起培養或 fura-2 AM 和細胞在15℃下作用，fura-2在細胞內之分布情況並無進一步之改善。本研究顯示fura-2 AM 在心肌細胞內均勻分布之最佳處理方式為心肌細胞和5uM 之fu ra-2 AM 於37℃下作用20分鐘後，再水解20分鐘，此可使84% 心肌細胞內fura-2呈均勻分布，且大都位於細胞質中。

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Balakrishnan, Saju. "Zytosolisches Calcium in murinen Hirnstamm-Motoneuronen wird differenziert von Mitochondrien reguliert". Doctoral thesis, 2006. http://hdl.handle.net/11858/00-1735-0000-0006-ABC0-A.

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Gonçalves, Alexandre Manuel Monteiro. "T3 HORMONE AS AN EFFECTIVE THERAPY FOR HEART FAILURE WITH PRESERVED EJECTION FRACTION: Effects on Ca2+ transients and contractility". Master's thesis, 2018. http://hdl.handle.net/10316/81936.

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Dissertação de Mestrado em Investigação Biomédica apresentada à Faculdade de Medicina
A insuficiência cardíaca com fração de ejeção preservada (ICFEP) constitui um frequente problema clínico, mas até hoje, nenhuma intervenção terapêutica parece modular o seu desfecho clínico. Alguns doentes com ICFEP possuem alterações no eixo hormonal da tiroide e é já conhecido o impacto da influência destas hormonas sobre o sistema cardiovascular. Neste projeto, testamos a hipótese de que administração oral preventiva com triiodotironina (T3) pode prevenir o desenvolvimento de ICFEP. Iniciou-se às 14 semanas de idade a administração oral de T3 (0.04 - 0.06 µg/mL) ou veículo em ratos ZSF1 obesos (ICFEP), utilizando ratos ZSF1 magros (CT) como controlo. A função tiroideia foi avaliada através de medições dos níveis plasmáticos de T3, T4 e TSH a cada 2 semanas e a dose de T3 administrada ajustada. No final do protocolo (24 semanas), foi realizada a avaliação ecocardiográfica, hemodinâmica e morfométrica dos animais. Os corações foram recolhidos e perfundidos enzimaticamente para isolamento de cardiomiócitos de forma a medir a contractilidade e a cinética dos transientes de Ca2+, usando a sonda fluorescente FURA-2. Cardiomiócitos isolados de ratos ICFEP apresentaram disfunção inotrópica e lusitrópica relativamente ao CT tal como observado pela diminuição na amplitude de contração, aumento no tempo até ao pico de contração e de relaxamento. A suplementação com T3 mostrou-se efetiva a normalizar a função. A maiores frequências de estimulação, a concentração de Ca2+ citoplasmático aumentou significativamente, mas o tratamento com T3 provou prevenir essa subida. Estes resultados constituem uma base de evidência promissora para os benefícios que a suplementação de T3 tem num subtipo particular de doentes com ICFEP com evidência de hipotiroidismo.
Heart failure with preserved ejection fraction (HFpEF) constitutes a major clinical problem, but to this day no therapy has effectively changed the course of the disease. Some HFpEF patients have alterations in the thyroid hormonal axis, and these hormones are known to influence cardiac function. In this project, we tested the hypothesis that preemptive triiodothyronine (T3) oral administration can prevent HFpEF development. Beginning at 14 weeks of age, ZSF1 obese rats (HFpEF) were orally administered with T3 (0.04 - 0.06 µg/mL) or vehicle, using ZSF1 lean rats (CT) as a control. Thyroid function was assessed through T3, T4 and TSH serum levels every two weeks and the dose was adjusted accordingly. At the end of the protocol (24 weeks), animals were evaluation by echocardiography, hemodynamics and morphometrics. The hearts were removed and enzymatically perfused to isolate cardiomyocytes for contractility and Ca2+ transient kinetics measurements using the FURA-2 fluorescent probe. Cardiomyocytes isolated from HFpEF rats shown inotropic and lusitropic impairments, as assessed by decreased contractile amplitude, increased time to peak contraction and relaxation, when compared to CT. T3 supplementation was found to be effective at normalizing these parameters. Higher stimulation frequencies led to cytoplasmic Ca2+ accumulation in HFpEF rat cardiomyocytes, while T3 treatment prevented this. These results constitute promising findings supporting the benefits of T3 supplementation in a certain subtype of HFpEF patients with evidence of hypothyroidism.

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Have, Meike von. "Charakterisierung ATP- und K+-induzierter Ca2+-Ströme und Untersuchung der Interaktion von ATP mit Ca2+-Kanälen an DRG-Neuronen und HEK-293-Zellen mittels Fura-2-Mikrofluorimetrie /". 2004. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=012924477&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

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Genty, Hélène. "Étude de l'association du réticulum endoplasmique lisse marqué par le récepteur du facteur autocrine de motilité avec les mitochondries". Thèse, 2003. http://hdl.handle.net/1866/14627.

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Kortus, Štěpán. "Vápníková signalizace magnocelulárních neuronů supraoptického jádra potkanů". Doctoral thesis, 2019. http://www.nusl.cz/ntk/nusl-409248.

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The magnocellular neurosecretory cells (MNCs) of the hypothalamus project axons from the supraoptic nucleus to the posterior pituitary gland, where they secrete either oxytocin or vasopressin into the circulation. Oxytocin is important for delivery at birth and is essential for milk ejection during suckling. Vasopressin primarily promotes water reabsorption in the kidney to maintain body fluid balance. The profile of oxytocin and vasopressin secretion is principally determined by the pattern of action potentials initiated at the cell bodies in the hypothalamus. MNCs principally secrete hormones from terminals in the pituitary, but the secretion also occurs from their dendrites in the supraoptic nucleus, where they diffuse and affect the neighbouring cells. Mechanisms controlling the oxytocin and vasopressin secretion from MNCs have been extensively studied over the last decades and it is assumed that the relationship between Ca2+ signalling, secretion from dendrites, and the firing patterns is essential in understanding the magnocellular neurosecretory system. In this project, we combine mathematical analysis and experimental measurements of Ca2+ activity of MNCs of transgenic rats expressing an arginine vasopressin-enhanced green fluorescent protein (AVP-eGFP) or oxytocin-monomeric red fluorescent...

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Liao, Ying-Chi, i 廖英錡. "Pyrolytic Study of 2-(2-Vinylstyryl)furan derivatives and 2-[2-(4-Methoxyphenyl)vinyl]benzo[b]thiophene". Thesis, 2006. http://ndltd.ncl.edu.tw/handle/32400694735627980679.

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碩士
國立中山大學
化學系研究所
94
Flash vacuum pyrolysis of 2-(2-vinylstyryl)furan derivatives via electrocyclization followed by dehydrogenation will give 2-(2-naphthalen-2-yl)furan analogues, on the other hand, FVP of 2-(2-vinylstyryl)furan derivatives via electrocyclization followed by [1,5]-H shift will give 3-(2-furyl)-1,2-dihydronaphthalene analogues. FVP of 2-[2-(4-methoxyphenyl)vinyl]benzo[b]thiophene gave three products: trans-4-(2-benzo[b]thiophen-2-ylvinyl)phenol, benzo[b]naphtha[1,2-d]thiophen-2-ol and 1H-6-thiacyclopenta[c]fluorene.

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Lavalle, Maria. "Rat protease-activated receptor–1 (rPAR1) expression and characterization in Sf9 cells". Thèse, 2014. http://hdl.handle.net/1866/11761.

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Connue pour son rôle dans la cascade de coagulation, la thrombine, une protéase à sérine, peut également agir par l’intermédiaire de PAR1, un récepteur activé par protéase et couplé aux protéines G liant le GTP (GPCR). La thrombine se lie et clive l’extrémité N-terminale du PAR1 entre l’Arg41 et la Ser42, exposant une nouvelle extrémité terminale qui agit elle-même comme un ligand. La thrombine et une séquence peptidique de cinq acides aminés, composée des résidus Ser42 à Arg46, nommée PAR1-AP, déclenchent dans diverses cellules de mammifères une réponse intracellulaire comportant une composante calcique. Dans cette étude, le système d’expression par baculovirus dans les cellules Sf9 d'insecte nous a permis d'exprimer le récepteur PAR1 du rat à la surface de ces cellules et de réaliser son couplage fonctionnel à leur signalisation intracellulaire (modèle rPAR1-Sf9). La composante calcique de celle-ci, en réponse au PAR1-AP, a ensuite été étudiée en détail à l’aide de la sonde fluorescente Fura-2 et de plusieurs inhibiteurs agissant sur les canaux calciques ou d'autres éléments de la cascade de signalisation du calcium intracellulaire. Lorsque le milieu extracellulaire contient du calcium (Ca2+), la thrombine ou PAR1-AP déclenchent un signal calcique qui consiste en une augmentation rapide de [Ca2+]i suivi d’un plateau relativement soutenu, puis d'un retour lent vers le niveau de base initial. En l'absence de Ca2+ dans le milieu extracellulaire, l'augmentation initiale rapide de [Ca2+]i est suivie d'un retour rapide vers le [Ca2+]i de base. À l’aide d’inhibiteurs de canaux calciques, tels que le lanthane, la nifédipine et le D-600, l'entrée du calcium du milieu extracellulaire dans les cellules est inhibée, abolissant le plateau soutenu de [Ca2+]i. L’inhibition de la pompe Ca2+-ATPase par la thapsigargine supprime la réponse au PAR1-AP après épuisement des sites de stockage de Ca2+intracellulaire. Le TMB-8 agit de façon discordante quant à l’inhibition de la libération de Ca2+ des sites de stockage intracellulaires. La réponse à PAR1-AP n’est pas affectée par le D-609, un inhibiteur de la phospholipase β. L’inhibition de la protéine kinase C (PKC) par le bisindolylmaléimide induit des oscillations en présence de Ca2+ extracellulaire et atténue fortement le signal calcique en absence de Ca2+ extracellulaire. En présence de Ca2+ extracellulaire, l’activation de la PKC par le PBDu tronque le flux de [Ca2+]i tandis que la réponse calcique est abolie en absence de Ca2+ dans le milieu extracellulaire. Le H-89, un inhibiteur de la protéine kinase A (PKA), cause une prolongation de la durée du plateau de [Ca2+]i dans un milieu riche en calcium et la suppression de la réponse à PAR1-AP lorsque le milieu extracellulaire est dépourvu de Ca2+. Les résultats obtenus nous permettent de conclure que la PKC et possiblement la PKA jouent un rôle critique dans la mobilisation du Ca2+ induite par le PAR1-AP dans le modèle rPAR1-Sf9.
Thrombin’s serine protease activity allows for it to have a role in both the coagulation cascade as well as through a GTP- binding protein coupled receptor (GPCR) known as the protease-activated receptor-1 (PAR1). Thrombin binds to PAR1 at the N-terminal, cleaving between Arg41 and Ser42, and unmasking a new N-terminal which acts as a tethered ligand. Thrombin and a five amino acid peptide composed of the sequence of residues Ser42 to Arg46, known as PAR 1-AP, has been shown to mediate a number of signalling mechanisms in mammalian cells, including a calcium signalling pathway. In the present study, the Sf9-baculovirus system allowed us to express the rat PAR1 (rPAR1-Sf9) on the cell surface and study its intracellular signalling. The calcium (Ca2+) signal was studied using the fluorescent probe Fura-2, and several Ca2+ channel inhibitors and calcium signal modulators were used to study the signal induced by PAR1-AP. In the presence of extracellular calcium [Ca2+]e, thrombin and PAR1-AP produced a Ca2+ signal which consisted of an initial spike in [Ca2+]i followed by a relatively maintained plateau and a slow return towards baseline. In the absence of Ca2+ in the extracellular space, the initial Ca2+ increase is followed by a quick return to baseline [Ca2+]i. Ca2+ channel inhibitors, lanthanum, nifedipine and D-600, inhibited the entry of Ca2+ from the extracellular space and abolished the plateau phase of the response to PAR1-AP. Inhibition of the Ca2+-ATPase with thapsigargin abolished the response to PAR1-AP after having depleted the Ca2+ stores involved in the initial spike in [Ca2+]i. TMB-8, expected to inhibit the release of Ca2+ from internal stores, inconsistently inhibited the [Ca2+]i response to PAR1-AP. The response elicited by PAR1-AP was not affected by D-609, an inhibitor of phospholipase Cβ. Inhibition of protein kinase C (PKC) with bisindolylmaleimide induced oscillations in the [Ca2+]i levels in the presence of extracellular Ca2+ while it significantly blunted the response in the absence of extracellular Ca2+. PDBu activation of PKC truncated the [Ca2+]i surge in Ca2+-rich conditions while abolishing it altogether in the absence of extracellular Ca2+. H-89 inhibition of protein kinase A (PKA) prolonged the plateau duration in Ca2+-rich medium while inhibiting the response to PAR1-AP in a Ca2+-deficient environment. Taken together, our results suggest that PKC and possibly PKA play a critical role in the mobilisation of Ca2+ in rPAR1-Sf9 by PAR1-AP.

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