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cis-Arenediols as versatile chiral synthons in the synthesis of prostaglandins, cyclitols, carbohydrates, and alkaloidsContla, Hector Luna 28 July 2008 (has links)
The oxidation of simple benzene derivatives by a mutant of Pseudomonas putida, called 39-D, produces cis-arenediols (1). The diols are enantiomerically pure and can be used as synthons for the preparation of a variety of interesting compounds because of their stereochemistry and the special array of functional groups.
See: Figure 1
cis -Toluenedio] (2) served as a chiral intermediate in an efficient synthesis of enone (3). which has been used to attain prostaglandin Fra and Neplanocin A. The same diol (2) was transformed into both enantiomers of a terpene synthon (4).
See: Figures 2, 3, 4
Oxidative functionalization of cis-chlorobenzenediol (5) afforded intermediates suitable for transformation into L-erythrose (6), conduritol C (7), dihydroconduritol C (8) and aminoconduntol F-4 (9).
See: Figures 5, 6, 7, 8
The application of this versatile synthetic protocol culminated in an approach to kifunensine (10), an important glycosidase inhibitor, which was approached according to the following retrosynthetic analysis:
See: Figures 10, 11, 12, 5, 14, 13
A detailed study of the nucleophilic opening of epoxide 13 was carried out in order to better understand the parameters of the diastereoselective functionalization of arenediols. Details are provided for the oxidative functionalization of chlorobenzenediol (5), the key compound in all of the projects discussed. / Ph. D.
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Total synthesis of the cyclic monoterpenoid pyrano[3,2-a]carbazole alkaloids derived from 2-hydroxy-6-methylcarbazoleGassner, Cemena, Hesse, Ronny, Schmidt, Arndt W., Knölker, Hans-Joachim 09 February 2015 (has links) (PDF)
The synthesis of seven pyrano[3,2-a]carbazole alkaloids has been achieved using their putative biogenetic precursor 2-hydroxy-6-methylcarbazole as key intermediate.
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Alkaloids from transannular iodoaminationsBrock, Elizabeth Anne January 2012 (has links)
This thesis is concerned with the development of transannular iodoamination methodology for the synthesis of pyrrolizidine, indolizidine and tropane alkaloids. Chapter 1 introduces the concept of a ‘transannular cyclisation’ and outlines the utility of such cyclisations in the synthesis of a range of [x.y.z]-azabicyclic alkaloids. Chapter 2 describes the development of a three step lithium amide conjugate addition, ring-closing metathesis and transannular iodoamination protocol for the preparation of the pyrrolizidine scaffold ([3.3.0]-azabicycle). Cyclisation of a hexahydroazocine occurs with concomitant N-debenzylation to give a single diastereoisomer of the corresponding C(7)-iodopyrrolizidine product, which is then elaborated to the known pyrrolizidine, (−)-7a-epi-hyacinthacine A1. Chapter 3 delineates an extension of the methodology described in Chapter 2, and an investigation into accessing alternate diastereoisomeric pyrrolizidine scaffolds via the transannular iodoamination process. These studies culminate in the synthesis of two pyrrolizidine alkaloids, (−)-hyacinthacine A1 and (−)-hyacinthacine A2. Chapter 4 details investigations into the further elaboration of the C(7)-iodopyrrolizidine scaffold synthesised in Chapter 2. A nucleophilic displacement reaction with azide leads to the synthesis of novel 7-deoxy-7-aminoalexine analogues, whilst radical-mediated substitution of the iodide by oxygen allows the synthesis and isolation of the pyrrolizidine alkaloid (−)-1-epi-alexine. Chapter 5 outlines the development of the transannular iodoamination reaction to facilitate the synthesis of the tropane architecture ([3.2.1]-azabicycle). A tandem lithium amide conjugate addition and aldol reaction sequence is followed by ring-closing metathesis to give the required aminocycloheptene. Subsequent treatment with iodine results in transannular cyclisation to give a single iodotropane product which, following elaboration culminates in the synthesis of (+)-pseudococaine. Chapter 6 contains full experimental procedures and characterisation data for all compounds synthesised in Chapters 2, 3, 4 and 5.
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Palladium-catalysed enolate arylation in the synthesis of isoquinolinesGatland, Alice Elizabeth January 2014 (has links)
<strong>Chapter 1. Introduction</strong> Scientific background on the development of homogeneous palladium-catalysed cross coupling reactions, focusing on the α-arylation reaction of enolates and its application to the synthesis of heteroaromatic compounds. The classical syntheses of isoquinolines are discussed, followed by an account of modern methods for their synthesis, including the recent α-arylation-based methodology developed by the Donohoe group. <strong>Chapter 2. Results and Discussion</strong> 2.1 Studies towards the development of a palladium-catalysed, C–H activation-based α arylation reaction of ketones, resulting in a C–H bromination/α-arylation sequence for the synthesis of isoquinolines and isoquinoline N-oxides. 2.2 The one-pot, four component coupling of a ketone, an acetal protected ortho-bromobenzaldehyde or ketone, an electrophile, and an ammonia source is described. This protocol, which ultimately provides C4 functionalised isoquinolines, is later extended to a novel α,α heterodiarylation protocol to furnish C4-aryl isoquinolines. 2.3 It is shown that the synthesis of 3 aminoisoquinolines can be achieved via the α arylation of nitriles. tert-Butyl cyanoacetate can act as a substitute for primary alkyl nitriles, with sequential α-arylation, in situ functionalisation, decarboxylation and cyclisation reactions provide C4 functionalised 3 aminoisoquinolines. 2.4 The synthetic utility of the α arylation based methodology for isoquinoline synthesis is exemplified by the total synthesis of the alkaloid berberine in 68% yield over five steps. This is followed by syntheses of pseudocoptisine, palmatine, dehydrocorydaline, and an unnatural fluorine containing analogue, in yields of 46%, 73%, 60% and 37%, respectively. 2.5 Finally, preliminary investigations demonstrate the utility of palladium-catalysed enolate arylation in the synthesis of β-carbolines.
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Synthèse totale de la lépadine B : plate-forme pour la découverte de nouvelles tranformations chimiquesBarbe, Guillaume 07 1900 (has links)
Dans ce document, serons détaillées les résultats de mes travaux de recherche d’études doctorales. Tout d’abord, nous discuterons de la synthèse totale de la lépadine B, la plus courte à paraître dans la littérature à ce jour. Cette synthèse, en plus de valoriser la synthèse asymétrique de pipéridines poly-substituées développée par l’équipe du professeur Charette, mettra à profit une utilisation originale d’une séquence de fermeture-ouverture de cycle par la réaction de métathèse d’alcènes. De plus, nous détaillerons une brève étude mécanistique de cette dernière nous ayant permis la proposition d’un mécanisme peu commun de ce type de séquence réactionnel et dont les conséquences expérimentales sont impressionnantes.
Au cours de cette synthèse, nous avons identifié un synthon d’une grande valeur synthétique. En effet, ne comportant pas moins que quatre centres chiraux, ce synthon pouvait être obtenu énantiopure en seulement trois étapes à partir de la pyridine. Ainsi, nous avons effectué une analyse structurale de ce synthon et avons envisagé une valorisation supplémentaire par une utilisation originale de la fragmentation de Grob. Dans ce contexte, nous avons développé une toute nouvelle synthèse de pipéridines 2,3,6-trisubstituées hautement régio- et diastéréosélective.
Afin de pouvoir réaliser la précédente méthodologie, nous avons dû étudier la réduction d’une amide en présence de groupements fonctionnels sensibles dans les conditions usuelles. Heureusement, l’année précédente nous avions développée une réaction hautement chimiosélective d’amides tertaires. Cette nouvelle réaction, qui a été fondamentalement inspiré par une méthodologie du professeur Charette sur l’activation d’amides, a permis la réduction d’amides tertiaires en présence de fonctions telles les cétone, ester, nitrile, époxyde, insaturations, etc.
Enfin, l’ensemble des connaissances acquises au cours de ces projets a permis l’élaboration d’une toute nouvelle stratégie de synthèse pour la préparation d’indolizidines et quinolizidines. Plus spécifiquement, nous avons développé la première séquence d’activation intramoléculaire et déaromatization asymétrique de la pyridine. Ceci permet d’avoir un accès aux squelettes indolizidine et quinolizidine avec des stéréosélectivités élevées, la nature insaturée de ces derniers laissant également place à une grande flexibilité synthétique. Dans ce contexte, nous allons détailler une très courte synthèse de trans-indolizidines. / In this document, the results of Ph.D. thesis will be detailed. First, we will discuss the synthesis of alkaloid lepadin B, the shortest to appear in the literature to date. This synthesis, in addition to validating the asymmetric synthesis of polysubstituted piperidines developed earlier by the group of Professor Charette, will highlight an original use of a ring-closing ring-opening alkene metathesis sequence. Also, a brief mechanistic study of the latter reaction will be detailed, a study which led us to propose an unusual mechanism for this reaction sequence and for which the experimental concequences are impressive.
During the total synthesis of lepadin B, we identified a synthon of great synthetic value. Indeed, containing not less than four chiral centres, that synthon could be obtained enantiopure through a short three-step synthesis from pyridine. We performed a structural analysis of this synthon and we envisaged an additional validating through an original use of the Grob fragmentation. Consequently, we developed a new highly regio- and diastereoselective synthesis of 2,3,6-trisubstituted piperidines.
To succesfully realize the latter methodology, it was required to perform an amide reduction in the presence of sensitive functionnalities under usual reduction conditions. Fortunatly, we had recently developed a set of conditions for the highly chemoselective reduction of tertiary amides. This new reaction, fundamentaly inspired by an amide activation methodology from Charette’s group, allowed the reduction of amides in the presence of functionalities such as ketone, ester, nitrile, epoxide, unsaturations, etc.
Finaly, the knowledge acquired by conducting this research allowed for the elaboration of a new methodology for the synthesis of indolizidines and quinolizidines. Specifically, we developed the first intramolecular pyridine activation-asymmetric dearomatization reaction of the pyridine. This led us to the highly stereoselective access to indolizidine and quinolizidine backbone, the unsaturated nature of which permitting a good degree of synthetic flexibility. In that context, we will detail a short synthesis of trans-indolizidines.
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Studium biologické aktivity alkaloidů izolovaných z Argemone grandiflora (Papaveraceae)I. / Study of biological activity of isolated alkaloids from Argemone grandiflora (Papaveraceae)I.Adamcová, Markéta January 2015 (has links)
Adamcová, M.: Study of biological activity of alkaloids isolated from Argemone grandiflora (Papaveraceae) I. Diploma thesis, Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Botany and Ecology, Hradec Králové 2015. The aim of this study was isolation of substances from total diethyl ether alkaloid extract of Argemone grandiflora Sweet, their identification and assessment of their inhibition activity towards acetylcholinesterase, butyrylcholinesterase and prolyl oligopeptidase. Using common chromatografic methods, four alkaloids were isolated, that was identified as (+)-laudanosine, protopine, (-)-argemonine a (-)-platycerine. These substances was tested for their inhibition activity IC50: (+)-laudanosine (IC50 AChE = 617,00 ± 46,55 μM, IC50 BuChE = 644,77 ± 55,52 μM, IC50 POP = not mesured yet); protopine (IC50 AChE = 229,98 ± 21,02 μM, IC50 BuChE = 208,87 ± 17,67 μM, IC50 POP ˃ 1000 μM); (-)-argemonine (IC50 AChE = 4677,75 ± 1241,08 μM, IC50 BuChE = 885,45 ± 119,50 μM, IC50 POP = 337 ± 83,1 μM); (-)-platycerine (IC50 AChE = 223,65 ± 19,61 μM, IC50 BuChE = 1651,25 ± 327,7 μM, IC50 POP = 687 ± 74 μM). In comparison with the standards galanthamine (IC50 AChE = 1,710 ± 0,065 μM, IC50 BuChE = 42,30 ± 1,30 μM) and huperzine A (IC50 AChE = 0,033 ± 0,001...
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Studium biologické aktivity alkaloidů izolovaných z Fumaria officinalis L. (Fumariaceae) II. / Study of biological activity of alkaloids isolated from Fumaria officinalis L. (Fumariaceae) II.Malý, Lukáš January 2014 (has links)
Malý, L.: Study of biological activity of alkaloids isolated from Fumaria officinalis L. (Fumariaceae) II. Diploma Thesis, Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Botany and Ecology, Hradec Králové 2014, 49 pp. Obtained diethylether extract of Fumaria officinalis L. was separated to fractions in column chromatography with petrol, chloroform and ethanol. Preparative TLC and crystalisation led to isolation of five alkaloids from fraction. Alkaloids were identified by GC-MS and NMR specters, optical rotation and melting point as protopine, cryptopine, (-)-fumaricine, (+)-fumariline and (+)-parfumidine. Isolated alkaloids were tested for their inhibition activity towards acetyl- and butyrylcholinesterase and towards prolyloligopeptidase. Activities were compared with standards. Natural inhibitor galanthamine showed IC50 AChE 1.710 ± 0.065 µM, IC50 BuChE 42.30 ± 1.30 µM. Best inhibition activity showed protopine (IC50 AChE 345.4 ± 24 µM, IC50 BuChE 239.6 ± 22.3 µM) and cryptopine (IC50 AChE 477.71 ± 47.33 µM, IC50 BuChE 270.82 ± 39.12 µM). The highest prolyloligopeptidase inhibition activity showed (+)-parfumidine with IC50 POP 99.2 µM, which was more active than used natural inhibitor baicaline (IC50 POP 605.9 ± 0.021 µM). Synthetic POP...
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Studium biologické aktivity alkaloidů izolovaných z Fumaria officinalis L. (Fumariaceae) I. / Study of biological activity of alkaloids isolated from Fumaria officinalis L. (Fumariaceae) I.Kostelník, Jan January 2014 (has links)
Kostelník, J.: Study of biological activity of alkaloids isolated from Fumaria officinalis L. (Fumariaceae) I. Diploma thesis, Charles University in Prague,Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Botany and Ecology, Hradec Králové 2014, 63 p. The aim of this study was to isolate alkaloids from joined fraction no. 55-67 (A2) obtained from the total alkaloid fraction of extract of Fumaria officinalis L. (Fumariaceae) plant. Using chromatography methods three alkaloids were isolated and then identified by structural analysis (GC-MS, NMR). Three alkaloids were isolated by using common chromagografic methods and then identified by structural analyses optical rotation and melting point as (-)-O- methylfumarophycine, (-)-sinactine a (-)-stylopine. Inhibitory activity of isolated alkaloids was assessed against human erythrocyte acetylcholinesterase, human butyrylcholineesterase and prolyl oligopeptidase. The results were expressed as IC50 values ((-)-stylopine: IC50 AChE and IC50 BuChE > 1000 μM, IC50 POP > 1000 mM; (-)-O-methylfumarophycine: IC50 AChE = 963.10 ± 135.98 µM, IC50 BuChE = 1771.0 ± 380.94 µM, IC50 POP - unmeasured; (-)-sinactine IC50 AChE = 632.0 ± 68.12 µM, IC50 BuChE = 8154.3 ± 981.42 µM, IC50 POP = IC50 POP = 52.9 ± 1.8 µM). None of alkaloids isolated showed...
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Etude des mécanismes moléculaires de résistance différentielle du mélanome malin aux vincalcaloïdes / Study of the molecular mechanisms of malignant melanoma differential resistance to vinca alkaloidsAttaoua, Chaker 19 June 2013 (has links)
Le mélanome malin (MM) est un cancer très réfractaire aux thérapies anticancéreuses, dont les vincalcaloïdes (VAs). Afin d'étudier le rôle de la GSTM1 (glutathion S-transférase 1) et la MRP1 (multidrug resistance protein 1) dans la résistance acquise du MM aux VAs, nous avons établi 4 modèles cellulaires de résistance à la vincristine (CAL1R-VCR), à la vindésine (CAL1R-VDS), à la vinorelbine (CAL1R-VRB) et à la vinflunine (CAL1R-VFL), par exposition continue de cellules du MM (CAL1-wt), pendant un an, à ces anticancéreux. L'expression d'ne GSTM1 fonctionnelle est spécifiquement observée (RT-PCR, western blot, activité GST totale) dans les cellules résistantes. Le curcumin (inhibiteur de GSTM1), la BSO (inhibiteur de synthèse de glutathion) et le MK571 (inhibiteur de MRP1), réduisent considérablement le résistance acquise à la VCR et à la VDS mais pas à la VRB ou à la VFL. Toutefois, tous ces VAs réduisent spécifiquement l'activité GSTM1. Ces données montrent l'implication différentielle de GSTM1 et MRP1 dans la résistance aux VAs. Pour déterminer les mécanismes moléculaires de cette chimiorésistance, nous avons réalisé une étude pangénomique (biopuces Affymetrix HG-U133 Plus 2.00) sur les lignées CAL1 (wt et R). Le regroupement hiérarchique (par Cluster et TreeView) des données des puces a révélé une similarité entre les profils d'expression génique de CAL1R-VRB et CAL1-wt mais aussi entre ceux de CAL1R-VCR et CAL1R-VDS. L'analyse bioinformatique (par IPA) des transcrits les plus différemment exprimés entre les lignées cellulaires, a mis en évidence 6 réseaux géniques connus pour leur rôle dans la chimiorésistance tumorale. Le programme FatiGO a révélé 3 termes biologiques sur-représentés (> 60%) dans CAL1R (ribosome, filaments intermédiaires du cytosquelette, récepteurs olfactifs) tandis que l'étude fonctionnelle (invalidation génique par siRNA, test de viabilité) de GPR143, KIT et SLC45A2 (gènes interagissant avec NF-κB et CCND1 (facteurs de la chimiorésistance tumorale), très exprimés dans CAL1-wt et muets dans CAL1R) a montré la faible tendance des deux premiers à être impliqués dans la résistance aux VAs. / Malignant melanoma (MM) is a very refractory tumor to anticancer therapies, including vinca alkaloïds (VAs). To investigate the role of GSTM1 (glutathione S-transferase μ1) and MRP1 (multidrug resistance protein 1) in MM acquired resistance to VAs, we established 4 cellular models of resistance to vincristine (CAL1R-VCR), to vindesine (CAL1R-VDS), to vinorelbine (CAL1R-VRB) and to vinflunine (CAL1R-VFL), by continuous exposure of MM cells (CAL1-wt), for one year, to these anticancer agents. The expression of a functional GSTM1 is specifically observed (RT-PCR, western blot, total GST activity) in resistant cells. Curcumin (GSTM1 inhibitor), BSO (glutathione synthesis inhibitor) and MK571 (MRP1 inhibitor), considerably reduce the acquired resistance to VCR and VDS but not that to VRB or VFL. However, all these VAs specifically reduce GSTM1 activity. These data show the differential involvement of GSTM1 and MRP1 in resistance to VAs. To determine the molecular mechanisms of this chemoresistance, we performed a pangenomic study (Affymetrix HG-U133 Plus 2.00 microarrays) on the CAL1 lines (wt and R). The hierarchical clustering (by Cluster and TreeView) of array data revealed a similarity between the gene expression profiles of CAL1R-VRB and CAL1-wt, but also between those of CAL1R-VCR and CAL1R-VDS. The bioinformatic analysis (by IPA) of the most differentially expressed transcripts between cell lines, highlighted 6 gene networks known for their role in tumor chemoresistance. FatiGO program revealed 3 biological terms overrepresented (>60%) in CAL1R (ribosome, intermediate filaments of cytoskeleton, olfactory receptors), while functional study (gene invalidation by siRNA, viability test) of GPR143, KIT and SLC45A2 (genes interacting with NF-kB and CCND1 (tumor chemoresistance factors), highly expressed in CAL1-wt and mute in CAL1R) showed the weak trend of the two formers to be involved in resistance to VAs.
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Alkaloidy Narcissus 'Dutch 'Master' (Amaryllidaceae) a jejich biologická aktivita. II. / Alkaloids of Narcissus'Dutch Master ' (Amaryllidaceae) and their biological activity. II.Dvořáková, Zdeňka January 2016 (has links)
Dvořáková Zdeňka: Alkaloids of Narcissus 'Dutch Master' (Amaryllidaceae) and their biological activity II. Diploma thesis 2016, Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Botany and Ecology. The content of this work was isolation of compounds from the selected fraction ND-6 obtained by column chromatography of Narcissus 'Dutch Master' alkaloid extract. Preparation of extract and its column chromatography was performed by Mrg. Daniela Hulcová as part of her doctoral studies. By the means preparative TLC was from fraction ND- 6 homolycorine type alkaloid (+)-O-methyllycorenine gained. Its structure was determined on the basis NMR, GC-MS analysis and optical rotation. The obtained data were compared with facts in known literature. By the isolated alkaloid was determined its cholinesterase inhibitory activity against acetylcholinesterase and butyrylcholinesterase. Its inhibitory activity was expressed as IC50 (M) and compared with known standards galanthamine, physostigmine, and Huperzine A. This alkaloid is inactive against cholinesterase (IC50 AChE > 1000 M, IC50 BChE > 1000 M). On the basis of gained results, we can evaluate this alkaloid from the point of view of cholinesterase inhibition as potentially unusable in the treatment of AD. Key...
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