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

Goniotalamina : atividade antitumoral e anti-inflamatória / Goniothalamin : antitumor and anti-inflammatory activities

Vendramini-Costa, Débora Barbosa, 1984- 07 May 2012 (has links)
Orientadores: João Ernesto de Carvalho, Ronaldo Aloise Pilli / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-09-28T18:41:42Z (GMT). No. of bitstreams: 1 Costa_DeboraBarbosaVendramini_D.pdf: 5920460 bytes, checksum: d6638ad4d3d0a96e4bbcdb55823f3254 (MD5) Previous issue date: 2012 / Resumo: A carcinogênese é um processo longo, multi-etapas, onde células normais progressivamente adquirem um fenótipo neoplásico. Sua origem é favorecida por fatores genéticos, exposição à carcinógenos químicos, infecções crônicas e incorporação de mutações em genes envolvidos com a regulação da homeostase celular. O crescente entendimento da biologia tumoral tem fornecido alvos moleculares para a triagem orientada de quimioterápicos e de agentes quimiopreventivos, geralmente de origem natural ou sintetizados com base em produtos naturais. A evolução da química orgânica permitiu que compostos naturais fossem sintetizados de forma econômica e aperfeiçoados quanto às suas propriedades físico-químicas, favorecendo sua disponibilidade. Esse trabalho teve como foco a goniotalamina, uma estiril-lactona naturalmente encontrada na forma enantiomérica (R) em plantas do gênero Goniothalamus (Annonaceae). Foram sintetizadas as formas (R), (S) e racêmica, que em painel de nove linhagens tumorais humanas levaram à inibição de crescimento e morte celular com elevada potência. Apesar da potência sobre a MCF-7 (carcinoma mamário responsivo ao estrógeno), estudos com estimulação estrogênica revelaram que a atividade da goniotalamina é independente da via hormonal. De qualquer maneira, a goniotalamina racêmica inibiu em 65% a proliferação da MCF-7 implantada em fibras semipermeáveis (hollow fiber) em camundongos. A citometria de fluxo revelou que o racemato de goniotalamina induz apoptose na linhagem tumoral de cólon HT-29 em baixa concentração (10 ?g/mL), com participação das caspases 8 e 9, sugerindo ativação das vias extrínseca e intrínseca. Houve também indução de apoptose na linhagem de melanoma humano SK-MEL-2, mas esse efeito diminuiu quando essa linhagem foi transfectada com Bcl-XL, inibidor apoptótico ligado à mitocôndria, sugerindo ativação principalmente da via apoptótica extrínseca, com ativação da via intrínseca para amplificação do sinal. A goniotalamina em suas três formas comprovou in vivo a atividade apresentada in vitro, pela inibição do desenvolvimento tumoral em modelo de tumor sólido e ascítico de Ehrlich, sem sinais de toxicidade nas doses efetivas. Esses resultados, aliados aos bons rendimentos na rota sintética, favoreceram a continuidade dos estudos com a forma racêmica. Considerando que aproximadamente 25% dos tumores estão relacionados com inflamações crônicas, a goniotalamina racêmica foi avaliada em modelos de edema de pata induzido por carragenina e por diversos mediadores (fosfolipase A2, histamina/serotonina, prostaglandina E2 e bradicinina), apresentando atividade anti-edematogênica em todos os modelos. Corroborando com esses resultados, a goniotalamina apresentou efeito antinociceptivo em modelos de algesia induzidos por processos inflamatórios. A goniotalamina inibiu o desenvolvimento de colite induzida por TNBS e o tratamento oral (30 mg/kg, três vezes por semana/três meses) preveniu o desenvolvimento de inflamação e câncer em animais deficientes em interleucina 10, sem apresentar sinais de toxicidade. Tais dados foram revelados após análise de dano macroscópico e microscópico (histologia) do cólon, havendo diminuição da expressão relativa dos genes para TNF? e MMP9, importantes no processo inflamatório e de invasão e metástase. Além disso, a goniotalamina diminuiu a incidência de metástase pulmonar em modelo de melanoma metastático. Os resultados obtidos e o perfil multi-alvos apresentado pela goniotalamina sugerem sua avaliação em terapias combinatórias para tratamento de processos inflamatórios crônicos e de câncer / Abstract: Carcinogenesis is a long process involving several steps, in which normal cells progressively acquire a neoplastic phenotype. Its origin is favored by genetic factors, exposure to chemical carcinogens, chronic infections and incorporation of mutations into genes involved in regulation of cellular homeostasis. The increasing understanding of tumor biology has provided molecular targets for screening of targeted chemotherapeutic and chemopreventive agents, usually from natural sources or synthesized based on natural products. The improvement of organic chemistry allowed the synthesis of natural products in an economic and refined way, with improvement on their physicochemical properties and availability. This work focuses on goniothalamin, a styryl-lactone naturally found on its enantiomeric form (R), in plants of Goniothalamus (Annonaceae) genus. The (R), (S) and racemic forms were synthesized and led to growth inhibition and cell death in a panel of nine human tumor cell lines, with high potency. Despite the potency against MCF-7 (breast carcinoma responsive to estrogen), estrogen stimulation studies revealed that the goniothalamin activity is independent of the hormone pathway. Anyway, racemic goniothalamin inhibited on 65% the proliferation of MCF-7 implanted into semi permeable fibers (hollow fiber) in mice. Flow cytometry analysis showed that low concentration of racemic goniothalamin (10 ?g/mL) leads colon tumor cell line (HT-29) to apoptosis with involvement of caspase 8 and 9, suggesting the activation of the extrinsic and intrinsic pathways. Apoptosis was also induced in human melanoma cell line SK-MEL-2, but the activity was decreased in SK-MEL-2 transfected with Bcl-XL, a mitochondrial related apoptotic inhibitor, suggesting mainly activation of the extrinsic apoptotic pathway, with activation of the intrinsic pathway to amplify the signal. Goniothalamin on its three forms comproved in vivo the in vitro activity by inhibiting tumor development in models of Ehrlich solid and ascitic tumor in mice, without signals of toxicity at the effective doses. These results, combined with good yields in the synthetic rout favored the racemic form to continue the in vivo studies. Considering that about 25% of tumors are related to chronic inflammation, racemic goniothalamin was evaluated in models of paw edema induced by carrageenan and various mediators (phospholipase A2, histamine/serotonin, prostaglandin E2 and bradykinin) displaying anti-edematogenic activity in all models. Corroborating these results, goniothalamin showed antinociceptive effect in models of algesia induced by inflammatory processes. It also inhibited the development of TNBS-induced colitis and oral treatment (30mg/kg, three times/week, three months) prevented the development of inflammation and cancer in interleukin-10 deficient mice, without signals of toxicity. These data were revealed after macroscopic and microscopic (histology) colon damage analysis, with decreased expression of TNF? and MMP9, which are important in inflammation, invasion and metastasis process. Furthermore, goniothalamin reduced the incidence of lung metastasis in a metastatic melanoma model. These results and the multitarget profile presented by goniothalamin suggest its evaluation in combinatory therapies for treatment of chronic inflammation and cancer / Doutorado / Biologia Celular / Doutor em Biologia Celular e Estrutural
2

Estudos sinteticos para a preparação de derivados furanofurona a partir do acido quinico / Sintetic studies for the preparation of furanefurones derivates from quinic acid

Jorge, Andre de Carvalho 18 December 2006 (has links)
Orientador: Lucia Helena Brito Baptistella / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-08T22:53:36Z (GMT). No. of bitstreams: 1 Jorge_AndredeCarvalho_M.pdf: 8483799 bytes, checksum: cbe192b8fe9d903f29cd3c2171475ffc (MD5) Previous issue date: 2006 / Resumo: O ácido quínico 1 é um metabólico de planta de ampla ocorrência natural que teve seu uso limitado no passado como precursor quiral em síntese de múltiplas etapas. Essa aplicação mudou em anos mais recentes quando várias publicações demonstraram toda a potencialidade sintética do seu esqueleto quiral altamente funcionalizado. O objetivo deste trabalho é a utilização de 1 para a síntese de biciclos furanofurona saturados e/ou insaturados com substituintes na junção dos anéis. O interesse nesses esqueletos bicíclicos se deve ao enorme potencial de atividade biológica que eles possuem, já que são idênticos àqueles encontrados em alguns compostos naturais isolados de plantas da família Annonaceae. Esses compostos são pertencentes a um grupo de moléculas conhecido como estiril lactonas, cujos membros, em sua grande maioria, apresentam significantes atividades citotóxicas em relação a células tumorais humanas. A seqüência proposta pode abrir novas alternativas para a preparação de análogos inéditos na serie das estiril lactonas, explorando a possibilidade de um aumento de cadeia através de uma reação de Wittig em carbonila de lactona. Estes novos análogos devem também ser submetidos a teste antiproliferativos, visando a análise de suas possíveis atividades farmacológicas. Os estudos efetuados permitem afirmar que a transformação do sistema ácido quínico em furanofuronas saturadas é bastante viável. A partir de 1 não foi possível a preparação do biciclo furanofurona insaturado 2, mas a rota proposta para os derivados furanofurona saturados 3, 4 e 5 se mostrou bastante versátil, abrindo possibilidades para a preparação de outros tipos de derivados. / Abstract: Quinic acid 1 is a plant metabolite widespread in nature that had in the past a limited use as a chiral precursor on organic synthesis. This application changed in recent years, and now several publications has shown the enormous synthetic potential of its highly functionalized skeleton. The purpose of this work is the use of 1 for the synthesis of furanefurone saturated and/or unsaturated bicycles with substitutes in the ring junction. The interest in these bicyclic skeletons is due to their enormous potential for biological activity, since they are identical to those found in some isolated natural compounds found in Annonaceae family plants. These compounds belong to a group of molecules known as styryl lactones, whose members, in its great majority, present significant cytotoxicity against human tumor cells. The proposed sequence can open new alternatives for the preparation of unknown analogous of this series, always exploring the possibility of carbon chain extention through a Wittig reaction in the lactone carbonyl group. These new analogues must also be submitted to some antiproliferative essays. The present studies allow confirming that the transformation quinic acid to furanefurone saturated systems is feasible. From 1, it was not possible the preparation of the unsaturated furanefurone 2, but the proposed sequence for 3, 4 and 5 has shown new possibilities for the synthesis of other derivatives. / Mestrado / Quimica Organica / Mestre em Química
3

Goniotalamina, epoxigoniotalamina, argentilactona e derivados : sinteses totais e atividades antiproliferativas contra celulas tumorais humanas / Goniothalamin, goniothalamin oxide and argentilactone: total syntheses and antiproliferative activies against cells of human cancer

Fatima, Angelo de 28 April 2005 (has links)
Orientador: Ronaldo Aloise Pilli / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-04T13:47:35Z (GMT). No. of bitstreams: 1 Fatima_Angelode_D.pdf: 6353488 bytes, checksum: a8d593bc18e70b70bdac0ab5c7789f96 (MD5) Previous issue date: 2005 / Doutorado / Quimica Organica / Doutor em Quimica
4

Total Synthesis of Anticancer Agent Deoxypodophyllotoxin and Antiviral F4-4 Demonstrating the Utility of the Intramolecular Styryl Diels-Alder (ISDA) Reaction

Saavedra Nova, Diana Isabel 01 March 2019 (has links)
The intramolecular styryl Diels – Alder (ISDA) reaction is a rare and unique [4+2] cycloaddition with potential in the syntheses of polycycles. Its utility is based on the formation of two rings and one stereocenter in a single step, making it an efficient method for the construction of lignan-type natural product targets. Detailed mechanistic studies with complex esters and the application to natural product synthesis has been limited due to drawbacks including the loss of aromaticity, producing slow reactivity, a potentially problematic thermal [1,3]-hydrogen shift, and electronic mismatch related to the substituents on the aryl functional groups. In this research, we found conditions that led to the successful application of the ISDA reaction on the total synthesis of the anticancer deoxypodophyllotoxin and the antiviral agent F4-4. Deoxypodophyllotoxin was synthesized in seven steps, which is a very concise synthesis for a complex lignan. Density functional theory was used to analyze the two components of the ISDA reaction, the [4+2] cycloaddition and the [1,3]-hydrogen shift. Several pathways were analyzed, and the rate determining step was determined to be the [4+2] cycloaddition. We also found that the [1,3]-hydrogen shift is assisted by di-tert-butylhydroxytoluene and is lower in energy than the [4+2] cycloaddition.The two targets chosen for this research have important biological activities. Deoxypodophyllotoxin is known as a potent anticancer agent related to podophyllotoxin. Podophyllotoxin is a more abundant lignan which is the precursor of the FDA approved drugs etoposide and teniposide, used for the treatment of lung and testicular cancer. Other biological activities of deoxypodophyllotoxin have been found including antibacterial, antiviral, and anti-inflamatory activity. Also, it was recently discovered that F4-4 possesses antiviral activities against Herpes simplex viruses 1 (HSV-1), 2(HSV-2), and H. zoster. Since both deoxypodophyllotoxin and F4-4 are not available in large quantities from natural sources, chemical synthesis is important for continuing research and drug development of these compounds.
5

Développement des sondes fluorescentes pour la détection de l’ADN quadruplex / Development of fluorescent probes for the detection of quadruplex DNA

Xie, Xiao 28 January 2015 (has links)
Les acides nucléiques simple-Brins contenant des répétitions de guanines peuvent former des structures secondaires non canoniques dites G-Quadruplexes, composées de plusieurs couches de quartets de guanine. Malgré de nombreuses études in vivo, les preuves de présence de structures quadruplexes in vivo restent indirectes. L’objectif de ce travail était la recherche de sondes fluorescentes capables de signaler la présence d'ADN quadruplex et détecter sa structure (topologie).Deux séries de sondes fluorescentes ont été envisagées et préparées : les colorants styryles (majoritairement distyryles) et les dérivés PDC-Coumarines. La conception de ces deux séries est basée sur l’échafaudage bisquinolinium pyrido¬dicarboxamide (PDC-360A), un ligand sélectif ayant une bonne affinité vis-À-Vis des structures d’ADN quadruplexes, mais qui est non-Fluorescent. En s’inspirant de cette molécule et du motif styryle, connu pour ses propriétés spectroscopiques, nous avons préparé une librairie de colorants distyryles. Une deuxième série, les dérivés PDC-Coumarine, est synthétisée afin d’introduire la propriété fluorescente de la coumarine dans le PDC par une liaison covalente.Les propriétés de colorant de ces deux librairies (65 composés) ont été étudiées en présence de nombreuses structures d’ADN (quadruplex et duplex) en utilisant un criblage par fluorescence sur microplaques et des méthodes de titration. Nos résultats montrent que certains colorants synthétisés possèdent une haute réponse fluorimétrique (facteur d’augmentation de fluorescence de 200 à 600) vis-À-Vis de différentes structures d’ADN et d’ARN quadruplex, ayant une très faible réponse fluorimétrique vis-À-Vis de l’ADN duplex. Cela permet de marquer sélectivement l’ADN quadruplex dans la solution ou sur les gels d’électrophorèse. Ces résultats représentent une première étape vers l’utilisation de ces sondes dans un contexte biologique, par exemple dans l’imagerie de fluorescence. / Single-Stranded nucleic acids containing guanine repeats can form non-Canonical secondary structures called G-Quadruplexes. These structures are composed of several guanine quartets, maintained by hydrogen bonds and metal cations (K+ or Na+) coordinated between G-Quartets. In spite of being well-Studied in vitro, the evidence for the presence of quadruplex DNA structures in vivo remains mainly indirect. The objective of this work was research of fluorescent probes that can signal the presence of quadruplex DNA and detect its structure (topology).Two series of fluorescent probes were considered and prepared: styryls dyes (mostly distyryls) and PDC-Coumarin derivatives. The design of these two series is based on the molecular scaffold of bisquinolinium pyridodicarboxamide (PDC-360A), a selective ligand with good affinity for quadruplex DNA structures but which is not fluorescent. Inspired by this molecule and the styryl motif, which is known for its spectroscopic properties, we considered a library of distyryles dyes. A second series, the PDC-Coumarin derivatives, was developed to introduce the fluorescence property of coumarin in the PDC by a covalent link. The properties of dyes of these two libraries (65 compounds) were studied in the presence of a number of DNA structures (quadruplex and duplex) by a fluorescent screening using microplate and titration methods. Our results show that some of synthesized dyes display high fluorescence response (i.e. fluorescence increase factor from 200 to 600) for different quadruplex DNA and RNA structures, while having a very low fluorimetric response for duplex DNA. This allows a selective visualization of quadruplex DNA in solution or in electrophoresis gel. These results represent the first steps towards the use of these probes in a biological context, for example in fluorescence imaging
6

Progress Towards the Development of Asymmetric Conditions for Intramolecular Heteroatom/Dehydro-Diels-Alder Reactions for Synthesizing Furo[3,4-c] Pyranones and Anticancer Podophyllotoxins

Mpaata, Peter 18 December 2023 (has links) (PDF)
Furo[3,4-c] pyranone is a unique bicyclic molecular structure found in bioactive sesquiterpene isobolivianine and in artificial cytotoxic stilbene derivatives. The structure of furo[3,4-c] pyranone is analogous to cyclopenta[c] pyran structure found in potent cytotoxic iridoids like catapol. Chiral substrates for intramolecular hetero-Diels-Alder (IHDA) reaction have been synthesized in yields ranging from 39% to 81%. These compounds undergo [4+2] cycloaddition via ambimodal/ bispericyclic process to give a mixture of furo[3,4-c] pyranone in yields ranging 40-70% and aryl tetralin lactone derivatives. Density functional theory (DFT) calculations have been performed to gain insight into the mechanism leading to the formation of these compounds. Podophyllotoxins are aryl tetralin lignans with great potential as lead compounds for anti-cancer and antibiotic agents. The bioactivity of these compounds is attributed to their unique stereochemistry that is not easy to synthesize. Chiral substrates for intramolecular dehydro-Diels-Alder (IDDA) reaction have been synthesized in moderate yields. These novel compounds have been used to synthesize aryl tetralin lactone cores by IDDA reaction. This work demonstrates the potential utility of asymmetric IHDA and IDDA reactions in the total synthesis of bioactive compounds featuring furo[3,4-c] pyranone core and aryl tetralin lactones found in anticancer podophyllotoxins.
7

Definisanje lipofilnosti, farmakokinetičkih parametara i antikancerogenog potencijala novosintetisane serije stiril laktona / Defining of lipophilicity, pharmacokinetic parameters and anticancer potential of newly synthesized series of styryl lactones

Lončar Davor 15 October 2018 (has links)
<p style="text-align: justify;">Reverzno-faznom tečnom hromatografijom pod visokim pritiskom primenom dva sistema<br />rastvarača ispitano je pona&scaron;anje i hromatografska lipofilnost prirodnih stiril laktona 7-(+)-<br />goniofufurona, 7-epi-(+)-goniofufurona, krasalaktona B i C i dvadeset njihovih<br />novosintetizovanih derivata i analoga. U ranijim ispitivanjima pokazalo se da ova jedinjenja<br />imaju veliki biolo&scaron;ki potencijal jer pokazuju zapaženu citotoksičnost prema vi&scaron;e humanih<br />tumorskih ćelijskih linija. Hromatografsko pona&scaron;anje jedinjenja uglavnom je u skladu sa<br />njihovom strukturom. Ustanovljene su linearne veze između hromatografskih retencionih<br />konstanti i većine in silico parametara lipofilnosti. Primenom hemometrijske QSRR analize<br />utvrđeni su veoma dobri multi linearni regresioni prediktivni modeli kvantitativne zavisnosti<br />između eksperimentalno dobijene hromatografske retencione konstante, koja defini&scaron;e<br />retenciju jedinjenja u čistoj vodi i in silico molekulskih deskriptora odnosno strukture<br />jedinjenja. Lipofilnost jedinjenja ima najveći uticaj na njihove farmakokinetičke, tj. ADME<br />(apsorpcija, distribucija, metabolizam, eliminacija) osobine. Definisani su i statistički<br />potvrđeni najbolji multi linearni regresioni modeli zavisnosti farmakokinetičkih parametara<br />stiril laktona i od drugih molekulskih deskriptora. In vitro citotoksična aktivnost jedinjenja<br />evaluirana je prema četiri nove humane maligne ćelijske linije: kancer prostate (PC3), kancer debelog creva (HT-29), melanom (Hs294T), adenokancer pluća (A549). Najaktivnije<br />novosintetizovano jedinjenje je triciklični 4-fluorocinamatni analog, koji ispoljava<br />nanomolarnu aktivnost (IC<sub>50</sub> 2,1 nM) prema ćelijama melanoma i aktivniji je preko 2250 puta od komercijalnog antitumorskog agensa doksorubicina (DOX). SAR analizom utvrđena je zavisnost između strukture i biolo&scaron;ke aktivnosti jedinjenja. Molekulskim dokingom ispitana je veza stiril laktona i ciljanog proteina značajnog za kancer prostate. Jedinjenja sa visokom inhibitornom aktivno&scaron;ću prema ćelijama kancera prostate imaju visok doking skor i mogu graditi koordinativno-kovalentnu vezu sa Fe<sup>2</sup>+jonom prisutnim u aktivnom centru enzima. 3D-QSAR analizom, koja je izvedena metodama komparativnih polja CoMFA i CoMSIA, formiran je značajan prediktivni model između hemijske strukture i biolo&scaron;ke aktivnosti stiril laktona.</p> / <p>The behavior and the chromatographic lipophilicity natural styryl lactone 7-(+)-<br />goniofufurone, 7-epi-(+)-goniofufurone, crassalactones B and C and twenty of their newly<br />synthesized derivatives and analogs were examined using reverse-phase high performance liquid chromatography in the two solvent systems. In previous studies it has been shown that these compounds have great biological potential toward several human tumor cell lines. Chromatographic behavior of the compounds is generally in accordance with their structure. The relationships between the chromatographic retention constants and the majority of their in silico lipophilicity parameters are linear. The application of chemometric QSRR analysis determined very good multiple linear regression predictive models of quantitative correlation between experimentally obtained chromatographic retention constant, which determines the retention of the compound in pure water and in silico molecular descriptors, i.e. the structure of the compound. The lipophilicity of the compounds has a major influence on their pharmacokinetics, i.e. ADME (absorption, distribution, metabolism, elimination) properties. The best multi-linear regression models depending on the pharmacokinetic parameters of styryl lactone and other molecular descriptors have been defined and statistically validated. In vitro cytotoxic activity of the compounds was evaluated according to four novel human malignant cell lines: prostate cancer (PC3), colon cancer (HT-29), melanoma (Hs294T), lung adenocarcinom (A549). The most active compound was tricyclic 4-fluorocinnamic analog, which exhibits a nanomolar activity (IC50 2,1 nM) toward melanoma cells. This compound is over 2250 times more active than commercial antitumor agent doxorubicin (DOX). SAR analysis has revealed a correlation between the structure and the biological activity of the compounds. Using the molecular docking the relationship of the styryl lactone and the target protein important for prostate cancer was examined. The compounds with high inhibitory activity against prostate cancer cells have a high docking score and are capable to form a coordinative-covalent bond with a Fe2+ ion present in the active centre of the enzyme. 3DQSAR analysis, which was performed by methods of comparative CoMFA and CoMSIA fields, has formed a good predictive model between chemical structure and biological activity of the styryl lactone.</p>
8

Steroselective Synthesis Of Bio-Active Styryllactones

Gholap, Shivajirao Lahu 05 1900 (has links)
The thesis titled “Stereoselective synthesis of bio-active styryllactones” comprises an introduction about styryllactones and three sections delineating the results and discussion about the synthesis of styryllactones and experimental section. Trees of the genus Goniothalamus of the plant family Annonaceae in South East Asia has been known for a long time for their proven use in folk medicine. The research group of McLaughlin isolated and characterized a series of styryllactones, possessing significant to marginal cytotoxic activity against human tumor cell lines. The structures and relative configurations of these compounds were determined either by X-ray crystallography or by extensive NMR spectral analysis. Classification of these styryllactones is based on the structural characteristics of the six different skeletons as shown in Figure 1. It was proposed by Shing et al. that the bio-synthesis of styryllactones 1-7 occur via the shikimic acid pathway. This proceeds through the formation of cinnamic acid from phenylalanine, followed by the incorporation of two acetate–malonate units activated as co-enzyme A, generating the styryl-pyrone, goniothalamin 9 a key styryllactone, which on further hydroxylation/oxidation leads to the formation of other styryllactones Section 1: Stereoselective synthesis of styryllactones containing furanofurone, pyrano-pyrone and styryl-pyrone structural units. In this section of the thesis, stereoselective total synthesis of furano-furone, pyrano-pyrone and styryl-pyrone type styryllactones (+)-7-epi-goniofufurone 1, (+)-goniofufurone 2, (+)goniopypyrone 3, (+)-goniotriol 4, (+)-9-deoxygoniopypyrone 5 and (+)-goniodiol 6 is discussed. It is anticipated that the masked tetrol 13, comprising an alkene tether and four contiguous hydroxy groups installed with definite configuration would serve as the intermediate for the synthesis of styryllactones 1-6. It is relied on exploiting the hydroxy directed lactonization via the oxidation of alkene in 13, and subsequent elaboration to styryllactones 1-6. Bis-dimethylamide 10, derived from D-(−)-tartaric acid was identified as the suitable precursor for the synthesis of 13. Synthesis of masked tetrol 13 is accomplished from 10 involving a combination of selective Grignard additions and a stereoselective reduction (Scheme 2). Section 2: Stereoselective synthesis of styryllactones containing tetrahydrofuran and furano-pyrone structural units This section deals with stereoselective synthesis of natural antitumor tetrahydrofuran containing natural product (+)-goniothalesdiol 8. Key features of the synthesis include a FeCl3 mediated formation of THF 15 with very high selectivity (Scheme 3). THF 15 is further elaborated into the furano-pyrone type styryllactones (+)-altholactone 7 and (−)-etharvensin 16 in good yields (Scheme 3). Section 3: Stereoselective total synthesis of (+)-cardiobutanolide Recently, a new styryllactone cardiobutanolide 20 was isolated from the stem bark of Goniothalamus cardiopetalus, together with four known styryllactones by Hisham et al. Stereoselective total synthesis of this natural product from D-(−)-tartaric acid is described in this section. Key features of the synthesis include the elaboration of the γ-hydroxy butyramide 17 obtained from the bis-dimethylamide 10, involving a combination of the addition of 1,3-dithian-2-yllithium and stereoselective reduction (Scheme 4). (For structural formula pl see the pdf file)
9

Synthesis of 2-Substituted-Pyrazolo[1,5-a]pyridines from N-Iminopyridinium Ylides

Fortier, Angélique 01 1900 (has links)
Cette thèse décrit le développement et la méthodologie pour la synthèse de 2-pyrazolo[1,5-a]pyridines à partir d’ylures de N-iminopyridinium et d’halogénures de styryle. Des dérivés de chaque ylure de N-iminopyridinium et d’halogénures de styryle ont été utilisés pour la synthèse de plusieurs composés avec un intérêt pharmaceutique. Le premier chapitre présente les précédents littéraires pour la synthèse de pyrazolopyridines. Spécifiquement trois types différents de synthèse seront présentés en détail. L’importance biologique de ces composés sera discutée. La vue d’ensemble des travaux développés dans notre groupe de recherche pour la synthèse des produits de départ sera présentée brièvement. Finalement, la science intéressante qui a apporté cette idée de recherche sera révélée. Le deuxième chapitre décrit les résultats des optimisations étudiées pour la synthèse des 2-phénylpyrazolo[1,5-a]pyridines à partir d’ylures de N-benzoyl-iminopyridinium et d’iodure de styryle. Chaque substrat de la réaction a été étudié individuellement afin d’être optimisé; les ratios, les solvants, la température du milieu réactionnel et le temps optimal de la réaction ont aussi été explorés. Le troisième chapitre présente l’étendue de la synthèse des pyrazolopyridines. L’étendue de la réaction inclut les dérivés des halogénures de styryle. L’étendue de la réaction a été élargie aux dérivés d’ylures de N-iminopyridinium et ils incluent des groupements donneurs d’électrons ainsi que des groupements pauvres en électrons. Des groupements exotiques d’iodure et de bromure de vinyle ont aussi été explorés. Le quatrième chapitre démontre les études mécanistiques que l’on a faites pour mieux comprendre les cycles catalytiques qui ont lieu durant la réaction. Des études de cyclisation avec les ylures de N-iminopyridinium ont été explorées pour les produits de départ suivants : iodure de styryle et phényl acetylène. / This thesis describes the development of a methodology for the one-pot synthesis of 2-pyrazolo[1,5-a]pyridines from N-iminopyridinium ylide and styryl-halide starting materials. Both N-iminopyridinium ylide derivatives and styryl-halide derivatives were employed for the synthesis of various pharmaceutically interesting pyrazolo[1,5-a]pyridines. The first chapter presents the literature precedents for the synthesis of pyrazolopyridines. More specifically, three different types of syntheses will be shown in detail. Furthermore, the biological importance of these compounds will be discussed. An overview of the developed methodologies previously carried out in our research group for the synthesis of the starting materials will be presented. Finally, the copper-catalyzed direct alkenylation of N-iminopyridinium ylides that brought about this research idea will be discussed. The second chapter describes the results of the optimization studies for the synthesis of 2-phenyl pyrazolo[1,5-a]pyridines from N-benzoyliminopyridinium ylides and styryl iodides. Each component of the reaction was individually screened and the loading ratios were optimized: e.g., solvent and temperature. The third chapter presents the scope of the pyrazolopyridine synthesis. The scope includes styryl iodide, –bromide and –chloride derivatives. The scope of the reaction was extended to N-iminopyridinium ylide derivatives and included electron donating and electron withdrawing groups. Substituted vinyl iodides and bromides were also investigated. The fourth chapter demonstrates the mechanistic studies conducted in order to obtain an accurate understanding of the catalytic cycles taking place during the reaction. Cyclization studies were explored for both styryl iodides and phenyl acetylene starting materials reacted with N-iminopyridinium ylides.
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Nove izostere i bioizostere prirodnih stiril-laktona: dizajn, sinteza i antiproliferativna aktivnost / Novel isosteres and bioisosteres of natural styryl lactones: design,synthesis and antiproliferative activity

Francuz Jovana 14 April 2015 (has links)
<p>U&nbsp; radu&nbsp; su&nbsp; ostvarene&nbsp; vi&scaron;efazne&nbsp; sinteze&nbsp; većeg&nbsp; broja&nbsp; analoga&nbsp; prirodnih&nbsp; stiril-laktona&nbsp; (+)-goniofufurona&nbsp; i&nbsp; 7-epi-(+)-goniofufurona&nbsp; polazeći&nbsp; iz&nbsp; D-glukoze.<br />Ispitana&nbsp; je&nbsp; in&nbsp; vitro&nbsp; citotoksičnost&nbsp; sintetizovanih&nbsp; analoga&nbsp; prema&nbsp; devet<br />malignih&nbsp; i&nbsp; jednoj&nbsp; zdravoj&nbsp; ćelijskoj&nbsp; liniji.&nbsp; Uspostavljeni&nbsp; su&nbsp; korelacioni&nbsp; odnosi<br />izmedju&nbsp; strukture&nbsp; i&nbsp; antiproliferati vne&nbsp; aktivnosti&nbsp; sintetizovanih&nbsp; proizvoda, pored&nbsp; toga&nbsp; uradjeni&nbsp; su&nbsp; i&nbsp; dodatni&nbsp; biolo&scaron;ki&nbsp; testovi&nbsp; koji&nbsp; se&nbsp; odnose&nbsp; na dokazivanje&nbsp; mehanizma&nbsp; citotoksičnog&nbsp; dejstva&nbsp; pomenutih&nbsp; stiril-laktona&nbsp; i analoga.</p> / <p>Multistep&nbsp; synthesis&nbsp; of&nbsp;&nbsp; a&nbsp; number&nbsp; of&nbsp; natural&nbsp; styryl&nbsp; lactones&nbsp;goniofufurone&nbsp; and&nbsp; 7-epi-goniofufurone&nbsp; analogues&nbsp; was&nbsp; achieved&nbsp;starting&nbsp; f rom&nbsp; D-glucose.&nbsp; In&nbsp; vitro&nbsp; cytotoxicity&nbsp; of&nbsp; newly&nbsp; synthetized analogues&nbsp; against&nbsp; nine&nbsp; human&nbsp; tumour&nbsp; cell&nbsp; lines&nbsp; and&nbsp; against&nbsp; a single normal cell line was evaluated. Structure-activity relationships were&nbsp; established&nbsp; for&nbsp; both&nbsp; natural&nbsp; products&nbsp; and&nbsp; analogues.&nbsp; Some additional&nbsp; biological&nbsp; tests&nbsp; related&nbsp; to&nbsp; the&nbsp; cell mechanisms&nbsp; underlying the&nbsp; cytotoxicity&nbsp; of&nbsp;&nbsp; the&nbsp; mentioned&nbsp; styryl&nbsp; lactones&nbsp; and&nbsp; analogues, were also carried out.</p>

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