A arilação seletiva de compostos orgânicos confere-lhes propriedades com amplas aplicações: em compostos de atividade biológica, inibidora da protease do vírus HIV-1, e de interesse como agroquímicos ou na engenharia de materiais. Em razão disso, novos métodos e reagentes tem sido desenvolvidos com essa finalidade. Sabe-se que a N-arilação de várias aminas, catalisadas por paládio, com haletos de arila e triflatos é tida como ferramenta importante a disposição do químico sintético. Do mesmo modo, publicou-se que a N-arilação de certos -amino ácidos por haletos de arila, procede-se facilmente quando catalisada por CuI. Alternativamente, a literatura cita outros métodos eficientes usando ácidos borônicos, compostos arilbismuto e compostos organochumbo. Neste trabalho foi estudada a arilação seletiva de ânions ambidentados pelo sal de iodo polivalente cloreto de difenil iodônio, em diferentes condições de reação, visando a otimização da síntese: 1) reação térmica (agitação magnética), sem catalisador, e em diferentes solventes, ou mistura de solventes; 2) reação sonoquímica, sem catalisador e em diferentes soluções; 3) reação térmica e sonoquímica na presença de catalisador CuCl (10%). Sacarinato de sódio, acesulfame de potássio, e ftalimida potássica foram escolhidos como ânions ambidentados derivados de sulfoimidas e imidas a serem arilados. No caso de N-fenil sacarina a quemiosseletividade e o melhor rendimento são observados com acetonitrila/água (1:1, v/v), sob refluxo para formação do par iônico intermediário (ou o iodano correspondente), seguido por fusão térmica na ausência de solvente. O acesulfame potássico, por sua vez, forneceu seletivamente produtos de N- ou O-fenilação, de acordo com as seguintes condições estabelecidas: 1) produto de fenilação por via térmica ou sonoquímica em etanol; 2) produto de O-fenilação, por via térmica ou sonoquímica em acetonitrila. A ftalimida potássica, na ausência de catalisador, é arilada em baixos rendimentos. A melhor condição de síntese é encontrada com acetonitrila e CuCl (10%), sendo 92% o rendimento por via sonoquímica e 78% por via térmica. A seletividade verificada foi analisada em termos das interações dos ânions ambidentados e dos solventes em questão. / The arylation of organic compounds gives place to a wide number of applications: concerning to their biological properties as HIV-1, protease inhibitor, as well as synthetic intermediates in pharmaceuticals, agrochemical and polymer chemistry. New methodologies and reagents have been developed as consequence of this. It is already known that N-arylation of several amines, catalyzed by palladium, with aryl halides and trifflates is a valuable tool to various reported organic synthesis. In the same way, it has been published that the N-arylation of certain -amino acids by aryl halides, proceeds smoothly when catalized by CuI. Alternatively, the literature reports other efficient methods using boranic acids, arylbismuth and organolead compounds. In the present work, it was studied the selective arylation of ambident anions by hypervalent iodine salts (chloride of diphenyl iodonium), in a different set of conditions, seeking the synthesis optimizations: 1) thermal reactions (silent mode, magnetic stirring), without catalyst, and, in different solvents or mixture of then; 2) sonochemical reactions, without catalyst, and in a different solvent composition; 3) thermal and sonochemical reactions carried out in the presence of (10%) CuCl as the catalyst. Sodium saccharinate, acessulfame K and potassium phthalimide were chosen as the ambident anions (derived from sulfonimides and imide functional groups) to be studied. In the N-phenyl saccharin case the chemioselectivity was achieved along the best yields when water/acetonitrila (1:1, v/v) solvent was employed in the step to form the ion pair (or the 3-iodane, intermediate), followed by the thermal fusion in the absence of solvent. The acessulfame K, for its turn, supplied selectively products of N- and O-arylation under the following established conditions: 1) N-phenylation in etanol through thermal and sonochemical approach; 2) O-phenylation product, in acetonitrila, by thermal and sonochemical method. Finally, arylation of potassium phthalimide with diaryliodonium is sluggish and gives low yields without catalyst. The best protocol to this synthesis was found with the solvent acetonitrile and (10%) CuCl catalyst addition, being 92% the yield of sonochemical reaction and 78% of the thermal one. The selectivity achieving was analyzed in accord with the solution interaction between the ambident anion and the solvent molecules.

Orientador: Fernando Antonio Santos Coelho / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-25T19:30:44Z (GMT). No. of bitstreams: 1 SouzaFilho_LuisGustavode1974-_D.pdf: 8902904 bytes, checksum: 85fa958ae1d753dea72d1d460737db4e (MD5) Previous issue date: 2014 / Resumo: Neste trabalho descrevemos uma nova abordagem para a síntese de ciclopentenonas substituídas com potencial atividade anti-inflamatória. As ciclopentenonas desempenham diversas atividades biológicas, a saber: anti-inflamatória, antineoplásica e antiviral. Devido a sua importância biológica sintetizamos várias ciclopentenonas utilizando adutos de Morita-Baylis-Hillman, como substrato. A sequencia se baseou no uso de uma reação de adição 1,4 catalisada por ródio, com adutos de Morita-Baylis-Hillman, levando à formação de cinamatos alfa-substituídos com elevada estereosseletividade E. A partir desses últimos, uma sequencia de etapas permitiu a preparação de 4 diferentes ciclopentenonas, em 7 etapas, com rendimentos globais variando de 10 a 30%. As ciclopentenonas sintetizadas tiveram seu perfil anti-inflamatório avaliado em modelos experimentais de inflamação não alérgica, edema de pata e peritonite ¿ in vivo e ensaio de agregação plaquetária ¿ in vitro. Demonstramos, através de tais experimentos, que essas ciclopentenonas inibem o processo inflamatório, ou seja, reduzem do edema de pata e a migração celular para a cavidade abdominal, além de uma possível indicação do mecanismo de ação dessas moléculas sobre a isoenzima ciclooxigenase tipo 2 (COX-2). Os ensaios de agregação plaquetária nos permitiram propor que o mecanísmo de ação possa ser por inibição de COX-2, já que tais ensaios mostraram que essas moléculas não inibem a enzima COX-1. Esse é o primeiro trabalho descrevendo a síntese de ciclopentenonas substituídas a partir de adutos de Morita-Baylis-Hillman / Abstract: This paper describes a new approach for the synthesis of substituted cyclopentenones with potential anti-inflammatory activity. The cyclopentenones play diverse biological activities, namely: anti-inflammatory, anticancer and antiviral. Due to their biological importance synthesize various cyclopentenones using Morita-Baylis-Hillman as substrate. The sequence was based on the use of a 1,4 addition reaction catalyzed by rhodium, with Morita-Baylis-Hillman, leading to the formation of alpha-substituted cinnamates with high stereoselectivity E. From the latter, a sequence of steps allowed the preparation of 4 different cyclopentenones in 7 steps with overall yields ranging from 10 to 30%. The cyclopentenones synthesized had their anti-inflammatory profile assessed in experimental models of non-allergic inflammation, paw edema and peritonitis ¿ in vivo and test platelet aggregation - in vitro. Demonstrated through such experiments , these cyclopentenones inhibit the inflammatory process, ie , reduce paw edema and cell migration into the abdominal cavity, as well as a possible indication of the mechanism of action of these molecules on the isoenzyme cyclooxygenase type 2 (COX-2). The platelet aggregation assays allowed us to propose that the mechanism of action may be through inhibition of COX - 2, since these trials have shown that these molecules do not inhibit COX-1 enzyme. This is the first paper describing the synthesis of substituted cyclopentenones from Morita-Baylis-Hillman adducts / Doutorado / Quimica Organica / Doutor em Ciências

Un grand nombre de 3,4-bisindolylmaléimides possède une activité inhibitrice des protéine-kinases. Les 3-isothiazolone-1,(1)-(di)oxydes pouvant être considérées comme des analogues de la maléimide, la fonctionalisation des 5-chloro- et 4,5-dichloro-3-isothiazolone 1,(1)-(di)oxydes par des réactions de couplage palladocatalysé de Suzuki-Miyaura, permet d'accéder aux analogues “thia” des 3,4-bisindolylmaléimides. La synthèse de sulfonamides primaires tels que les dérivés 4-(hétéro)aryl substitués du benzènesulfonamide comme inhibiteurs potentiels de l'anhydrase carbonique, a également été envisagée dans ce travail.Une collection de matériaux hybrides constitués de nanoparticules de palladium adsorbées sur des nanostructures de carbone a été préparée et testée dans des réactions de couplages palladocatalysés, comme catalyseurs en milieu hétérogène. Le plus efficace d'entre eux, associant des nanoparticules de palladium stabilisées par le dodécanethiol et adsorbées sur des nanotubes de carbones “multi-walled”, a été employé afin de préparer vingt-quatre nouveaux dérivés 4-(hétéro)aryl substitués du benzènesulfonamide. L'échec de l'utilisation de ce catalyseur dans les reactions de fonctionalisation des isothiazolone-1,(1)-(di)oxydes nous a contraints à employer un catalyseur plus conventionnel, le PdCl2(dppf)•CH2Cl2.Le dernier volet de ce projet visait à concevoir des catalyseurs à base de nanoparticules de palladium encapsulées dans des nanofibres de carbone “grafitisées” (nanoréacteurs). Une série de nanoréacteurs a pu être préparée et nous avons étudié l'effet du confinement généré à l'intérieur de la nanofibre, sur la réaction palladocatalysée de Suzuki-Miyaura. / 3,4-bisindolylmaleimides possess an inhibitory activity against protein kinase. Because 3-isothiazolone-1,(1)-(di)oxide can be considered as maleimide analog, 5-chloro and 4,5-dichloro-3-isothiazolone-1,(1)-(di)oxide were functionalised using a palladium-catalysed Suzuki-Miyaura cross-coupling reaction achieving the “thia” analogs of 3,4-bisindolylmaleimides. We were also interested in the preparation primary sulfonamides such as 4-(hetero)aryl substituted benzenesulfonamides as carbonic anhydrases inhibitors.A series of hybrid materials comprising palladium nanoparticles adsorbed on carbon nanostructures has been prepared and tested as heterogeneous catalysts of palladium-mediated cross-coupling reactions. The best catalyst, resulting in palladium nanoparticles stabilised by dodecanethiol adsorbed on multi-walled carbon nanotubes, was employed in Suzuki-Miyaura reactions for the preparation of twenty-four new 4-(hetero)aryl substituted benzenesulfonamides. As this catalyst failed in the functionalisation of isothiazolone-1,(1)-(di)oxides, this latter was realised using a more conventional catalyst, PdCl2(dppf)•CH2Cl2.A last part of the project aimed to the conception of catalysts made of palladium nanoparticles encapsulated in graphitised carbon nanofibres (nanoreactors). We prepared a series of nanoreactors and we studied the effect of the confinement inside the nanofibre channel on the Suzuki-Miyaura cross-coupling reaction.

La synthèse de la 5-azagalanthamine, un analogue azoté de galanthamine, utilisée dans le traitement palliatif de la maladie d’Alzheimer, a été envisagée dans le cadre d’une étude de relations structure-activité. Durant cette thèse nous avons examiné quatre voies de synthèse afin d’accéder à la 5-azagalanthamine. La première voie est basée sur la réaction de Pictet-Spengler afin de fermer le dernier cycle de l’azagalanthamine. De nombreuses tentatives ont été effectuées sur différents types de substrats mais cette stratégie s’est révélée inefficace. La deuxième approche consiste en une oxydation d’anilide ortho-substitué par un groupement méthoxy, avec un réactif à base d'iode hypervalent pour accéder à une spirodiènone, un intermédiaire clé de la synthèse. En effectuant cette réaction nous n’avons pas obtenu le produit attendu, mais une 1,2-dispirodiénone, un motif inhabituel, et très rare. Après avoir optimisé les conditions réactionnelles, nous avons étudié la généralité de la réaction avec d'autres substrats. La modélisation moléculaire ainsi que des études de voltammétrie cyclique ont été réalisées (Chabaud, L.; Hromjakova, T.; Rambla, M.; Retailleau, P.; Guillou, C. Chem. Commun. 2013, 49, 11542-11544. Hromjakova, T.; Retailleau, P.; Grimaud, L.; Gandon, V.; Chabaud, L. et Guillou, C. accepté EurJOC, 2015, DOI 10.1002/ejoc.201501160).Ensuite nous avons examiné l’approche basée sur le couplage intramoléculaire pallado-catalysé. Après les premiers résultats encourageant avec le substrat modèle nous avons réalisé une optimisation des conditions réactionnelles. Une étude de généralité de la réaction avec d'autres substrats a été effectuée. Malheureusement, il s’est avéré que la substitution sur le cycle aromatique n’était pas bien tolérée conduisant à de faibles rendements. Par conséquent cette méthodologie n’a pas pu être appliquée à la synthèse de l’azagalanthamine. Dans la dernière voie de synthèse examinée nous avons repris les travaux antérieurs entrepris dans notre laboratoire concernant la réaction de Heck intramoléculaire. La diminution de la longueur de la chaîne liant les deux cycles a permis d’obtenir des résultats très prometteurs. / The synthesis of 5-azagalanthamine, the analogue of galanthamine that is used in Alzheimer treatment, was investigated for structure - activity relationship studies.During this thesis I explored four synthetic approaches with the aim of preparing the 5-azagalanthamine. The first one is based on a Pictet-Spengler reaction used for ring closure of the last cycle of azagalanthamine. We carried out many tests on various types of substrate but this strategy has proved to be ineffective. The second approach consists of an oxidation of ortho-methoxy substituted anilide by hypervalent iodine reagent to access a spirodienone, a key intermediate of the synthesis. Interestingly this reaction did not result in the expected compound but we observed the formation of an unusual motif, the 1,2-dispirodienone. After conditions optimisation we studied the scope and limitations with others substrates. Molecular modelling and cyclic voltammetry studies were also carried out (Chabaud, L.; Hromjakova, T.; Rambla, M.; Retailleau, P.; Guillou, C. Chem. Commun. 2013, 49, 11542-11544. Hromjakova, T.; Retailleau, P.; Grimaud, L.; Gandon, V.; Chabaud, L. and Guillou, C. accepté EurJOC, 2015, DOI 10.1002/ejoc.201501160).Then we investigated an approach based on palladium-catalysed intramolecular coupling. After the first encouraging results with the model substrate, we did optimization of the reaction conditions and the study of substrate scope. Unfortunately we discovered that the substitution was not well tolerated and decreased the yield. Therefore this methodology could not be applied to the synthesis of the azagalanthamine. In the last approach we used previous work of our laboratory on the intramolecular Heck reaction. The reduction of the length of the linker between both cycles showed to be beneficial. We obtained promising results with this approach.

This thesis describes synthetic studies directed towards the total synthesis of the nakafuran and florlide marine natural products. Chapter One provides an overview of the importance of natural products to current medicinal chemistry and describes how the "supply issue" associated with these biologically derived compounds can be resolved through the process of total synthesis. Two families of marine natural products, the nakafurans and the florlides, are introduced as synthetic targets and strategies utilising a type II intramolecular Diels-Alder (IMDA) reaction to achieve their total synthesis are delineated. The efficient preparation of regio- and stereodefined vinyl coupling fragments via hydrostannylation and hydrohalogenation methodology is described in Chapter Two. The palladium-catalysed cross-coupling of these fragments, via Stille or Negishi coupling methodology, yielded dienes which were successfully advanced to IMDA triene precursors. Chapter Three describes investigation of the type II IMDA reaction to give bicyclo[4.3.1]decene carbocyclic skeletons. A facile acid-catalysed 6,7-alkene to 7,8-alkene olefinic isomerisation, via a proposed oxonium intermediate, and the inability to appropriately functionalise the desired adducts impeded progress along the synthetic route. Molecular modelling was conducted to investigate the causes of this unexpected reactivity. Investigations in Chapter Four describe the successful synthesis and cyclisation of homomethyl triene analogues prepared via application of enyne metathesis chemistry. The use of an exo-cyclopropylcarbinyl fragmentation was found to be unsuccessful as a means of installing the desired 6-methyl-bicyclo[4.3.1]decan-2-one core with a competing endo-ring expansion giving rise to a bicyclo[4.4.1]undecane ring system. Chapter 5 summarises the above results and gives a brief discussion of the future potential of this research to provide for a total synthesis of the nakafuran and florlide natural products.

Le système spirocyclique (7,5) est un motif récurrent dans un certain nombre de produits naturels tels que les Micrandilactones ou les Rubriflordilactones. Ces structures polycycliques représentent un réel défi synthétique pour les chimistes organiciens puisqu'elles présentent au moins neuf centres stéréogènes dont plusieurs sont quaternaires. L'objectif principal de ce travail était de développer de nouvelles réactions de cycloaddition [3+2] et de les utiliser comme étape clé afin d'obtenir rapidement et efficacement le squelette polycylique de ces composés. La première partie de ces travaux a été consacrée au développement d'une réaction de cycloaddition [3+2] intra- et intermoléculaire mettant un jeu un nouveau partenaire dipolarophile, les γ-alkylidènes-buténolides. Cette étape clé conduit à la formation de cycloadduits hautement fonctionnalisés de façon rapide et efficace avec d'excellents rendements et de façon hautement chimio-, régio- et diastéréosélective. De plus, des calculs théoriques ont permis d'appréhender le mécanisme réactionnel entre un 2-diazo-1,3-cétoester et la protoanémonine catalysé par un sel de rhodium mis en jeu dans ce type de processus et ainsi d'expliquer les résultats obtenus.Dans une deuxième partie, deux approches aux cœurs ABC et CD de la micrandilactone C ont été développées mettant respectivement en jeu une cycloaddition [3+2] formellement intermoléculaire utilisant un lien de type acétal de silicium et suivie par une réaction de Diels Alder. Ainsi, le motif tétracyclique devrait être rapidement accessible après quelques aménagements de la voie de synthèse initiale. / The spiro (7, 5) ring system is a recurring structural moiety in numerous natural products such as Micrandilactones and Rubriflordilactones. In term of complexity, these polycyclic structures represent a synthetic challenge for organic chemist. Indeed, these molecules present at least nine stereogenic centres including several quaternary ones. The main goal of this work was to use unprecedented partners in the [3+2] cycloaddition reaction to obtain quickly and efficiently the polycyclic core of those natural products. The first part of these studies was dedicated to the development of an intra- and intermolecular [3+2] cycloaddition using for the first time a γ-alkylidene-butenolide dipolarophile. This approach provides rapid and facile access to highly functionalised polycyclic molecules along with excellent regio-, chemo- and stereoselectivities. In addition, thanks to computational studies an overall picture of the mechanism of the intermolecular rhodium catalysed [3+2] cycloaddition between 2-diazo-1,3-ketoester and protoanemonin was apprehended, and experimental results have been rationalised.Finally, two approaches to the ABC and CD cores of Micrandilactone C were developed using respectively a formal intermolecular [3+2] cycloaddition reaction in presence of a silicon acetal linker followed by a Diels Alder reaction. The ACDE tetracyclic moiety should be quickly accessible after few modifications of the initial strategy.

<p>Grupno-strukturna analiza naftnih kiselina izolovanih iz srednjih uljnih&nbsp;komercijalnih frakcija vojvođanske nafte &bdquo;Velebit&rdquo; rađena je analizom IR-,&nbsp;¹H- i&nbsp;¹³C NMR- i ESI-MS spektara niske rezolucije. Određeno je &scaron;est klasa&nbsp;karboksilnih kiselina op&scaron;te molekulske formule C_nH_2n-ZO₂. To su karboksilne&nbsp;kiseline u opsegu masa 240-466 sa 15-31 C atoma u molekulu koje su&nbsp;grupisane u pet cikloalkil Z-serija: monociklična- (C_nH_2n-2O₂, 14.72%),&nbsp;biciklična- (C_nH_2n-4O₂, 34.63%), triciklična- (C_nH_2n-6O₂, 25.03%), tetraciklična- (C_nH_2n-8O₂, 10.04%), pentaciklična klasa karboksilnih kiselina (C_nH_2n-10O₂, 4.99%) i jedna alkanska klasa kiselina sa alkil grupama otvorenog niza (C_nH_2nO₂, 10.57%).</p><p>Razdvajanjem na bazi različite kiselosti i njihove rastvorljivosti u vodi na&nbsp;određenim pH vrednostima u rasponu od pH 2-10 dobijeno je devet užih&nbsp;frakcija kiselina. Ekstrakcijom sa etrom u vodi nerastvornih kiselina u rasponu&nbsp;od po jedne pH jedinice dobijena je sledeća distribucija masa: 9.57% (pH 10),&nbsp;12.69% (pH 9), 5.91% (pH 8), 4.85% (pH 7), 2.44% (pH 6), 11.71% (pH 5),&nbsp;23.94% (pH 4), 16.76% (pH 3) i 10.12% (pH 2). Razdvajanjem kiselina na bazi&nbsp;njihove kiselosti oko 50% mase kiselina ekstrahovano je od pH 2-4, znači u&nbsp;grupi jačih kiselina. Masenom spektrometrijom niske rezolucije ESI-MS na&nbsp;pH 4 vidi se da su u sme&scaron;i kiselina skoncentrisane kiseline sa vi&scaron;e prstenova u&nbsp;alkilnom delu sa maksimumom na tricikličnim kiselinama (36.50%), dok su&nbsp;pojedinačno najzastupljenije tetraciklične strukture kiselina C₂₀H₃₂O₂(4.43%) i&nbsp;C₂₁H₃₄O₂(4.56%). Na pH 8 biciklične- i triciklične strukture su zastupljene&nbsp;ukupno sa 65.02% sa maksimalno zastupljenim kiselinama sa 20-26 C atoma&nbsp;u molekulu, a izdvajaju se C₂₂H₃₈O₂ (5.26%)&nbsp;biciklične- i C₂₄H₄₂O₂(7.01%)&nbsp;triciklične strukure, a od tetracikličnih struktura kiselina izdvaja se C₂₄H₄₀O_2&nbsp;(4.77%). Na pH 10 najzastupljenije izolovane kiseline su aciklične, odnosno&nbsp;masne kiseline zastupljene sa 25.28%, a najdominantnije su strukture&nbsp;C₂₁H₄₂O₂ (4.83%), dok su ostale klase kiselina ujednačene po svom masenom&nbsp;udelu u odnosu na sastav u ukupnoj polaznoj sme&scaron;i kiselina.&nbsp;Drugi deo rada obuvata derivatizaciju izolovanih prirodnih naftnih kiselina.&nbsp;Sintetizovani su funkcionalni kiseonični metil-, etil-, n-butil-,&nbsp; terc-butil- i&nbsp;benzil-derivati naftnih kiselina kao i funkcionalni azotni derivati: amidi i anilidi&nbsp;naftnih kiselina. Sinteze navedenih estara rađene su klasičnim postupcima i&nbsp;modifikovanom metodom esterifikacije u kiselo-katalizovanim uslovima&nbsp;upotrebom mikrotalasa kao ko-katalizatora, &scaron;to je imalo za cilj skraćenje&nbsp;reakciong vremena i pobolj&scaron;anje ekolo&scaron;kih sintetskih uslova.<br />Modifikacijom sinteze metilnaftenata MT-zagrevanjem 48 puta je skraćeno&nbsp;vreme trajanja sinteze, prinosi ni promenom reakcionih parametara (vreme,&nbsp;snaga MT) nisu bitno promenjeni. Strukturnom analizom ESI-MS spektra&nbsp;polaznih kiselina i metilnaftenata dobijenih metilovanjem naftnih kiselina&nbsp;utvrđeno je da je odnos klasa u dobroj podudarnosti. Prinos estara u ovoj&nbsp;sintezi je 95.47%. Esterifikacija naftnih kiselina etil alkoholom rađena je u&nbsp;uslovima kisele katalize uz konvencionalno zagrevanje (91.76%), a&nbsp;modifikacijom metode MT-zagrevanjem (150 W) reakciono vreme je skaćeno&nbsp;96 puta (92.19%). Esterifikacija naftnih kiselina n-butil alkoholom rađena je uz&nbsp;sumpornu kiselinu kao katalizator i uz konvencionalno zagrevanje (94.24%), a&nbsp;u uslovima MT-zagrevanja (150 W) 72 puta je skraćeno reakciono vreme&nbsp;(61.15%). Sinteza terc-butilnaftenata rađena je prevođenjem naftnih kiselina u&nbsp;hloride a zatim reakcijom sa terc-butil alkoholom nastaju terc-butilnaftenati&nbsp;(80.17%). Modifikovanom metodom klasične reakcije esterifikacije naftnih&nbsp;kiselina terc-butil alkoholom katalizovanom sumpornom kiselinom u uslovima&nbsp;MT-zagrevanja (150 W) ostvaren je prinos od 85.49% a vreme trajanja reakcije&nbsp;je 5 minuta. Sinteza benzilnaftenata rađena je prevođenjem naftnih kiselina u&nbsp;hloride a zatim reakcijom sa benzil alkoholom nastaju benzilnaftenati&nbsp;(84.43%), a modifikovanom metodom klasične kiselo-katalizovane&nbsp;esterifikacije naftnih kiselina benzil alkoholom u uslovima MT-zagrevanja&nbsp;(150 W) ostvaren je prinos od 85.49% uz reakciono vreme od 5 minuta.&nbsp;Sinteza amida naftnih kiselina rađena je iz hlorida reakcijom sa amonijakom.&nbsp;Prinos čistih amida je 65.74%, a reakcija amidacije sa amonijakom trajala je&nbsp;15 minuta. Strukturnom analizom ESI-MS spektra amida naftnih kiselina&nbsp;utvrđen je grupno-strukturni sastav amida. Među strukturama amida naftenskih&nbsp;kiselina takođe su dominantne biciklične- i triciklične strukture, kao i u sme&scaron;i&nbsp;slobodnih kiselina. Sinteza anilida naftnih kiselina rađena je iz hlorida reakcijom sa anilinom. Prinos čistih anilida je 96.48%, a reakcija amidacije anilinom trajala je 30 minuta. Strukturnom analizom ESI-MS spektra anilida naftnih kiselina utvrđen je grupno-strukturni sastav proizvoda, anilida. Među strukturama anilida naftenskih kiselina takođe su dominantne biciklične- i triciklične strukture kao i u sme&scaron;i slobodnih kiselina.</p><p>U trećem delu ovog rada ispitivana je biolo&scaron;ka aktivnost naftnih kiselina&nbsp;auksinskog i giberelinskog tipa, njihov uticaj na ožiljavanje reznica,&nbsp;ukorenjivanje bočnih grana i mikroizdanaka biljaka, na aktivnost biljnih&nbsp;hormona, kao i na usvajanje metalnih jona kod biljaka.&nbsp;</p><p>Aktivnost naftenskih kiselina utvrđena je pomoću tri in vitro&nbsp; biolo&scaron;ka testa.&nbsp;&bdquo;Koleoptil test&rdquo;, rađen je na dva supstrata, odnosno na semenu ozime p&scaron;enice&nbsp;novosadske sorte Partizankai jare p&scaron;enice takođe novosadske sorte Venera.&nbsp;Referentna aktivnost u testu rađena je sa -naftilsirćetnom 3-indolsirćetnom&nbsp;kiselinom. U oba testa ustanovljen je približno isti odnos aktivnosti rastvora&nbsp;naftenskih kiselina i aktivnosti standardnih biljnih hormona. &bdquo;Test inhibicije&nbsp;klijanja&rdquo; semena rađen je sa semenom crne slačice, Brasscia nigra. Najveći&nbsp;uticaj naftenskih kiselina na inhibiciju klijanja postignut je u rasponu&nbsp;koncentracija kiselina od 10^-7&nbsp;-10^-8&nbsp;mol/L (0.05-0.01 mg/L). Testovi za &scaron;est užih&nbsp;frakcija dobijenih iz sme&scaron;e ukupnih kiselina razdvajanjem na bazi različite&nbsp;rastvorljivosti pri različitim pH vrednostima pokazuju istu aktivnost kao&nbsp;3-indolsirćetna kiselina (0.5 mg/L), a da je frakcija izdvojena iz vodenog&nbsp;rastvora na pH 7 takođe aktivna ali u poređenju sa 3-indolsirćetnom kiselinom&nbsp;to je 10 puta niža aktivnost. Hormonska aktivnost giberelenskog tipa ispitivanih&nbsp;kalijumovih soli naftenskih kiselina utvrđena je &bdquo;Endosperm testom&rdquo;, u kojem je&nbsp;određivana aktivnost amilaze spektrofotometrijskim praćenjem povećanja&nbsp;koncentracije redukujućih &scaron;ećera u endospermu semena tretiranog ječma i&nbsp;poređena sa aktivno&scaron;ću rastvora giberelinske kiseline (GA3). Rezultati ovih&nbsp;testova pokazuju da delovanjem vodenih rastvora užih frakcija naftenskih&nbsp;kiselina u koncentraciji 1.0 mg/L (3.5 x 10^-6mol/L)frakcija izolovana pri pH 8&nbsp;ima aktivnost koja je približno u opsegu aktivnosti giberelina koncentracije&nbsp;10^-2-10^-3&nbsp;mg/L.&nbsp;</p><p>Natrijum-naftenati u koncentraciji od 10^-6&nbsp;<br />do 10^-8&nbsp;mol/L stimuli&scaron;u formiranje&nbsp;adventivnih korenova kod reznica suncokreta pa je broj korenova po biljci 40&nbsp;puta veći kod biljaka koje su bile potopljene u rastvor natrijum-naftenata u&nbsp;odnosu na one koje su bile potopljene u vodu, a sličan efekat utvrđen je i pri&nbsp;tretiranju bočnih grana suncokreta.&nbsp;</p><p>Ožiljavanje drvenastih biljaka rađeno je na reznicama bele topole (Populus&nbsp;alba) i reznicama američke crne topole (Populus deltoides). Uočen je jasan&nbsp;inhibitomi efekat na rast korenčića i izbojka u vodenom medijumu sa 10^-4&nbsp;mol/L&nbsp;naftenskih kiselina, dok je tretman od 24 časa doprineo većem broju korenčića&nbsp;na donjih 5 cm reznice, kao i ukupnog broja korenčića nego kod kontrole.&nbsp;</p><p>U testu ukorenjivanja mikroizdanaka kod hrizantema najveći broj korenova&nbsp;dobijen je nakon tretmana sa rastvorom koji sadrži 10 &micro;mol/L ukupnih naftenata&nbsp;i tretmanom sa 50 &micro;mol/Lfrakcijom kiselina izolovanom pri pH 7. Oba rezultata&nbsp;su na nivou aktivnosti 3-indolbuterne kiseline koncentracije 10 &micro;mol/L&scaron;to znači&nbsp;da u ovom slučaju frakcionacija nije neophodna.&nbsp;</p><p>Efekti natrijum-naftenata na ukorenjivanje praćeni su merenjem nivoa totalnih&nbsp;peroksidaza i amilaze, &nbsp;kao i sadržaja redukujućih &scaron;ećera i ukupnih proteina u&nbsp;bazalnim delovima reznica bagrema(Rozaszin-AC).&nbsp; Nakon 1; 3 i 6 dana&nbsp;reznice su uzete za biohemijske analize. U svakom slučaju, aktivnosti&nbsp;IAA-oksidaze i amilaze su se povećavale do trećeg dana, &nbsp;a zatim smanjuje.&nbsp;Efekat je bio jače izražen posle tročasovnog tretmana sa natrijum-naftenatima&nbsp;u poređenju sa &scaron;estočasovnim tretmanom i kontrolom. Sadržaj rastvornih&nbsp;proteina je bio povećan jedan dan posle tretmana, smanjen trećeg i ponovo povećan &scaron;estog dana, osim za &scaron;estočasovni tretman natrijum-naftenatima, kada je efekat bio sasvim suprotan.</p><p>Test uticaja naftnih kiselina na nivo kadmijuma u biljkama pokazuje fiziolo&scaron;ko delovanje naftnih kiselina na snižavanje nivoa te&scaron;kih metala u biljci, u ovom slučaju kadmijuma. Ispitivan je efekat niske koncentracije natrijum-naftenata (10^-7&nbsp;mol/L) na ukupan sadržaj Cd u pojedinim frakcijama interćelijskog prostora kao i unutar ćelija, kao i na neke fiziolo&scaron;ke i biohemijske parametre kod mladih biljaka soje koje su uzgajane u prisustvu kadmijum-hlorida koncentracije 1 mmol/L. Prisustvo naftenata smanjuje sadržaj ukupnog kadmijuma kako u korenu tako i u stablu i listovima u proseku za oko 40% i ublažava &scaron;tetne efekte kadmijuma na aktivnost nitrat-reduktaze kao i na sadržaje fotosintetskih pigmenata.</p><p>Tretman biljaka niskim koncentracijama natrijum-naftenata utiče na&nbsp;akumulaciju nekih esencijalnih elemenata kod mladih biljaka soje. Prisustvo&nbsp;naftenata (10^{-7 &nbsp;}mol/L) značajno povećava sadržaj Mn, Fe, Zn i Ni u korenu, ali&nbsp;u stabljici i listovima samo sadržaj Fe i Mn. U korenu, sadržaj Mn je četiri puta&nbsp;veći a sadržaji Fe, Zn i Ni su povećani 17%, 60% i 68%, respektivno.&nbsp;</p><p>Ispitivanja na celeru i mrkvi su potvrdila da uticaj naftenata na mineralnu&nbsp;ishranu zavisi od primenjenog elementa i da je način preuzimanja određenih&nbsp;jona različit, &scaron;to ima za posledicu ili povećanje ili smanjenje sadržaja pojedinih&nbsp;jona u nekim delovima biljaka. Mlade biljke celera i mrkve, gajene u hranljivom&nbsp;medijumu, tretirane su natrijumovim solima naftenskih kiselina (10^-7&nbsp;mol/L)&nbsp;folijarno ili prisustvom u hranljivom medijumu. Jedino je tretman putem&nbsp;prisustva naftenata u hranljivom medijumu smanjio svežu masu korena i&nbsp;nadzemnog dela oko 20% kod obe biljke.Oba tretmana uticala su na sadržaj&nbsp;Fe, Cu, Mn, Mg i Ca kod biljaka celera i Fe, Mn, Zn i Na kod biljaka mrkve.&nbsp;Kod biljaka celera do&scaron;lo je do smanjenja sadržaja navedenih nutrienata dok je&nbsp;u korenu biljaka mrkve do&scaron;lo do povećanja sadržaja Fe za 45%, Mn za 70% i&nbsp;Zn za 37%. Kod ovih biljaka prisustvo naftenata u hranljivom medijumu dovelo&nbsp;do smanjenja mase korenova i nadzemnih delova, &scaron;to je potpuno suprotno od&nbsp;rezultata dobijenih kod biljaka soje.&nbsp; Folijarnim tretmanom je značajno<br />povećana masa nadzemnog samo kod celera.</p> / <p>Group-structural analysis of naphthenic acids isolated from middle&nbsp;commercial fractions of Vojvodina oil &bdquo;Velebit&rdquo; was performed with the&nbsp;analysis of IR-,<br />¹H- and&nbsp;¹³C NMR- and ESI-MS low resolution spectrums.&nbsp;Six classes of carboxylic acids of the general molecular formula C_nH_2n-ZO_2&nbsp;were determined. These are carboxylic acids with mass range of 240-466&nbsp;with 15-31 C atoms in molecule which are grouped in five cycloalkyl&nbsp;<span style="font-size: 12px;">Z-series: monocyclic- (C_nH_2n-2O₂, 14.72%), bicyclic- (C_nH_2n-4O₂, 34.63%),&nbsp;</span><span style="font-size: 12px;">tricyclic- (C_nH_2n-6O₂, 25.03%), tetracyclic- (C_nH_2n-8O₂, &nbsp;10.04%), pentacyclic&nbsp;</span><span style="font-size: 12px;">class of carboxylic acids (C_nH_2n-10O₂, 4.99%) and one alyphatic class of&nbsp;</span><span style="font-size: 12px;">acids with open chain alkyl groups (C_nH_2nO₂, 10.57%).</span></p><p>By fractioning on the basis of different levels of acidity and their solubility in&nbsp;water with pH values ranging from pH 2-10 nine subfractions of acids were&nbsp;obtained. By extraction with ether in water undissolved acids in the range of&nbsp;one pH unit the following distribution of mass was performed: 9.57%&nbsp;(pH 10), 12.69% (pH 9), 5.91% (pH 8), 4.85% (pH 7), 2.44% (pH 6), 11.71%&nbsp;(pH 5), 23.94% (pH 4), 16.76% (pH 3) and 10.12% (pH 2). By fractioning&nbsp;acids on the basis of their acidity about 50% of acid &nbsp;mass was extracted at&nbsp;pH 2-4, i.e., in the group of stronger acids. Low resolution mass&nbsp;spectrometry ESI-MS shows that at pH 4 acids with more rings in the alkyl&nbsp;<br />section were concentrated in the mixture with maximum at tricyclic acids&nbsp;(36.50%), while individually tetracyclic acid structures C₂₀H₃₂O₂ (4.43%) and&nbsp;C₂₁H₃₄O_2&nbsp;(4.56%) were most prominent. At pH 8 bicyclic- and tricyclic&nbsp;structures are represented &nbsp;together by 65.02% with acids with 20-26 C&nbsp;atoms in molecule being represented the most, and C₂₂H₃₈O₂&nbsp; (5.26%)&nbsp;bicyclic- and C₂₄H₄₂O₂(7.01%) tricyclic structures stand &nbsp;out, while with&nbsp;tertacyclic acid structures C₂₄H₄₀O₂ (4.77%) stands out. At pH 10 most&nbsp;represented isolated acids are acyclic, i.e., fatty acids which are&nbsp;represented by 25.28%, with the most dominant C₂₁H₄₂O_2&nbsp;structures&nbsp;(4.83%), while the other classes &nbsp;of acids are well balanced in their mass&nbsp;share in relation to the composition of the overall initial acid mixture.</p><p>The second part of this work deals with derivatization of the isolated natural&nbsp;naphthenic acids. Functional oxygen methyl-, ethyl-, n-butyl-, tert-butyl and&nbsp;benzyl-derivatives of naphthenic acids as well as functional nitrogen&nbsp;derivatives: amides and anilides of naphthenic acids were synthesized. The&nbsp;syntheses of the above mentioned esters were performed by conventional&nbsp;methods and by a modified method of esterification in acid-catalyzed&nbsp;conditions using microwaves as a co-catalyst with the aim of shortening the&nbsp;reaction time and improving the ecological synthetic conditions.&nbsp;</p><p>By modification of methyl naphthenates synthesis using MT-heating the&nbsp;time period for synthesis is reduced 48 times and the yield does not&nbsp;significantly change even after the reaction parameters (time, MT power)&nbsp;have been altered. Using structural analysis of ESI-MS spectrum of initial&nbsp;carboxylic acids and the methyl naphthenates obtained through methylation&nbsp;of naphthenic acids it was establishedthat the class ratio shows great&nbsp;compatibility. The esters yield in this synthesis is 95.47%. The esterification&nbsp;of naphthenic acids with ethyl alcohol done under the conditions of acid&nbsp;catalysis with conventional heating (91.76%), and with the modified method&nbsp;MT-heating (150 W) the reaction time is reduced 96 times (92.19%). The&nbsp;esterification of naphthenic acids with n-butyl alcohol was performed using&nbsp;sulphuric acid as a catalyst with conventional heating (94.24%), and under&nbsp;MT-heating conditions (150 W) reaction time was 72 times&nbsp; shorter&nbsp;(61.15%). The synthesis of&nbsp; tert-butyl naphthenates was performed by&nbsp;conversion of naphthenic acids into chlorides, followed by the reaction with&nbsp;tert-butyl alcohol which resulted in tert-butyl naphthenates (80.17%). By the&nbsp;modified method of conventional reaction of esterification of naphthenic&nbsp;acids using tert-butyl alcohol catalysed with sulphuric acid in MT-heating&nbsp;conditions (150 W) the yield was 85.49% and reaction time was 5 minutes.&nbsp;The synthesis of benzyl naphthenates was performed by conversion of&nbsp;naphthenic acids into chlorides, followed by a reaction with benzyl alcohol&nbsp;which produces benzyl naphthenates (84.43%), whereas the modified&nbsp;method of conventional acid-catalysed esterification of naphthenic acids&nbsp;using benzyl alcohol under MT-heating (150 W) conditions the yield was&nbsp;85.49% with the reaction time of 5 minutes.&nbsp;</p><p>The synthesis of naphthenic acid amides was done from chlorides by&nbsp;reaction with ammonia. The yield of pure amides was 65.74%, and the&nbsp;reaction of amidation with ammonia lasted for 15 minutes. The structural&nbsp;analysis of ESI-MS spectrum of naphthenic acid amides determined the&nbsp;group-structural composition of amides. With the structures of amides of&nbsp;naphthenic acids bicyclic- and tricyclic structures are also dominant, as in&nbsp;the mixture of free acids. The synthesis of naphthenic acid anilides were&nbsp;performed from chloride by reacting with aniline. The yield of pure anilides&nbsp;<br />was 96.48%, and the reaction of amidatation lasted for 30 minutes. The&nbsp;structural analysis of ESI-MS spectrum of naphthenic acid anilides&nbsp;determined the group-structural composition of anilide products. With the&nbsp;structures of anilides of naphthenic &nbsp;acids bicyclic- and tricyclic structures&nbsp;are also dominant, as in the mixture of free acids.</p><p>The third part of this work tests the biological activity of naphthenic acids of&nbsp;auxine and gibberellinic type, their influence on the rooting of cuttings,&nbsp;lateral branches and microshoots of plants, on the activity of plant&nbsp;hormones as well as on the metal ions uptake by plants.&nbsp;</p><p>The activity of naphthenic acids was determined using three in vitro&nbsp;biological tests. &bdquo;Koleoptil test&rdquo;, was done on two substrates, namely the&nbsp;seed of winter wheat of the Partizankasort and the spring wheat of the&nbsp;Venerasort. The referential activity in the test was performed with&nbsp;&alpha;-naphthylacetic- and 3-indolacetic acid. Both tests showed approximately&nbsp;the same ratio of activity of naphthenic acid solutions and standard plant&nbsp;hormones. &bdquo;Germination Inhibition Test&rdquo; of the seed was performed using&nbsp;<br />Brasscia nigraseed. The greatest influence of naphthenic acids to&nbsp;germination inhibition was achieved in the acid concentration ranging from&nbsp;10^-7-10^-8&nbsp;mol/L (0.05-0.01 mg/L). The tests for six narrow fractions obtained&nbsp;from the overall mixture of acids through fractioning on the basis of different&nbsp;solubility at different pH values show the same activity as 3-indolacetic acid&nbsp;(0.5 mg/L), with the fraction isolated from the aqueous solution at pH 7 also&nbsp;active but in comparison to 3-indolacetic acid this activity was 10 times&nbsp;lower. Hormone activity of gibberellinic type of the potassium salts of&nbsp;naphthenic acids was determined using &ldquo;Endosperm Test&rdquo; where amylase&nbsp;<br />activity was determined by spectrophotometric measuring of the increase of&nbsp;the concentration of reducing sugars in endosperm in the treated barley&nbsp;seed which was then compared to the activity of the gibberellic acid solution&nbsp;(GA3).&nbsp; The results of these tests indicate that the activity of aqueous&nbsp;solutions of narrow fractions of naphthenic acids in the concentration of&nbsp;1.0 mg/L (3.5 x 10^-6&nbsp;mol/L)the fraction isolated &nbsp;at pH 8 has the activity&nbsp;which is approximately within the range of activities of gibberellin of the&nbsp;concentration of 10^-2-10^-3&nbsp;mg/L.&nbsp;</p><p>Sodium salts of naphthenic acids in concentrations of 10^-6&nbsp;do 10^-8&nbsp;mol/L&nbsp;stimulated formation of adventitious roots in&nbsp;<span style="font-size: 12px;">sunflower cuttings even by a&nbsp;</span><span style="font-size: 12px;">factor of 40 compared with control, the effect being also observed lateral&nbsp;</span><span style="font-size: 12px;">branches of interspecies sunflower hybrids. The obtained results suggest&nbsp;</span><span style="font-size: 12px;">the possibility of using naphthenic acids as a means for rooting of plant&nbsp;</span><span style="font-size: 12px;">cuttings.</span></p><p>Rooting of hardwood plants was investigated on the cuttings of white poplar&nbsp;(Populus alba) and black poplar (Populus deltoides). The distinct inhibitory&nbsp;effect on the root and shoot growth in water culture was detected in the&nbsp;concentration of naphtenic acids 10^-4&nbsp;mol/L, but 24-hour treatment raised&nbsp;the number roots on undermost 5 cm of the cutting, as well as the total&nbsp;number of roots, comparing to the control.</p><p>In the test of rooting microshoots ofchrysanthemum the highest number of&nbsp;<span style="font-size: 12px;">roots was achieved after the treatment with solution containing 10 &micro;mol/L of&nbsp;</span><span style="font-size: 12px;">total napthenates, as &nbsp;well as after the treatment with fraction of naphthenic&nbsp;</span><span style="font-size: 12px;">acids which was isolated at pH &nbsp;7 in concentration of 50 &micro;mol/L. Both results&nbsp;</span><span style="font-size: 12px;">are on the level of activity of 3-ndolbutyric acid in concentration of 10 &micro;mol/L&nbsp;</span><span style="font-size: 12px;">which suggests that in this case ractionation is not necessary.</span></p><p>The effects of sodium naphthenates on rooting were investigated by&nbsp;measuring the level of total peroxidases and amylase, along with the&nbsp;contents of reducing sugars and total proteins in basal parts of cuttings of&nbsp;black locust (Rozaszin-AC). After 1; 3 and 6 days cuttings were taken for&nbsp;biochemical analysis. In all cases, the activities of IAA-oxidase and amylase&nbsp;increased to the third day and showed a decrease afterwards. The effect&nbsp;was more pronounced after the three-hour treatment with sodium&nbsp;naphthenates, compared to the six-hour treatment and control. The content&nbsp;of soluble proteins increased one dayafter the treatment and decreased to&nbsp;the third and again increased to the sixth day, an exception being the&nbsp;six-hour treatment with sodium naphthenate, when the effect was&nbsp;completely opposite.</p><p>The test of naphthenic acids influence on the level of cadmium in plants&nbsp;showed physiological activity of naphthenic acids on the decrease of the&nbsp;level of heavy metals, &nbsp;in this case cadmium, in the plant. The effect of low&nbsp;concentrations (10^-7&nbsp;mol/L) of sodium naphthenate on total content of Cd in&nbsp;the intercellular space and inside cells, as &nbsp;well as on some physiological&nbsp;and biochemical parameters of young soybean plants grown in the&nbsp;presence of 1 mmol/L solution of cadmium chloride was investigated.&nbsp;Presence of naphthenate reduced in average by 40 % content of total and&nbsp;intracellular Cd in root, stem and leaves and alleviated the harmful effect of&nbsp;<br />Cd on activity of nitrate reductase and content of photosynthetic pigments.</p><p>Treatment of soybean plants with low concentrations of sodium&nbsp;naphthenate influenced the accumulation ofsome essential elements by the&nbsp;young plants. The presence of naphthenates (10^-7&nbsp;mol/L) significantly&nbsp;increased content of Mn, Fe, Zn and Ni in root, but in stem and leaves&nbsp;increased only contents of Fe and Mn. Inroot, the content of Mn increased&nbsp;four times while contents of Fe, Zn and Ni increased by 17%, &nbsp;60% and 68%&nbsp;respectively compared to the control.</p><p>Investigations on celery and carrot&nbsp; confirmed that the influence of&nbsp;naphthenates on mineral nutrition depends on the applied element and that&nbsp;the way of uptake of certain ions is different, which results in either increase&nbsp;or decrease of the contents of some ions in certain parts of plants. Young&nbsp;plants of celery and carrot, were grown in the nutrient medium and treated&nbsp;with sodium salts of naphthenic acids (10^-7&nbsp;mol/L) over the leaves or with its&nbsp;presence in the nutrient medium. Only the treatment based on the &nbsp;presence&nbsp;of naphthenates in the nutrient medium resulted in the decrease of the fresh&nbsp;mass of root and aboveground part by about 20% for both plants. Both&nbsp;treatments had influence on the content of Fe, Cu, Mn, Mg and Ca in the&nbsp;plants of celery and Fe, Mn, Zn and Na in the plants of carrots. In the plants&nbsp;of celery the content of the mentioned nutrients was decreased, while in the&nbsp;root of plants of carrot &nbsp;the content was increased, Fe by 45%, Mn by 70%&nbsp;and Zn by 37%. With these plants &nbsp;the presence of naphthenates in the&nbsp;nutrient medium caused the reducing roots and aboveground parts, which is&nbsp;completely opposite from the results obtained with soybean plants. The&nbsp;treatment by leaves significantly increased the mass of aboveground part&nbsp;only with celery.</p>

L’oxydase de l’acide 1-AminoCyclopropane Carboxylique (ACC Oxydase, ACCO) catalyse la formation de l’éthylène, hormone essentielle à la vie des plantes. L’ACCO catalyse l’oxydation de l’ACC en éthylène en présence de dioxygène et de deux électrons (fournis in vitro par l’ascorbate). L'activité de l'enzyme requière également, pour des raisons encore incomprises, la présence de CO2 sous la forme d'ions bicarbonates. Il s’agit d’une enzyme qui contient un ion fer(II) dans un environnement non-hémique au site actif. Etant donné l’importance de l’éthylène chez les plantes, l’ACCO, ainsi que les autres enzymes impliquées dans sa biosynthèse, ont été très étudiées durant les vingt dernières années. Cependant, peu d’études ont porté sur le rôle de l’ion métallique et le mécanisme d’action ou sur les surprenants processus d’inactivation subis par l’enzyme. L’ACCO est en effet une enzyme connue pour son instabilité. Nous avons tout d’abord entrepris une caractérisation physicochimique et biochimique de l’enzyme. Le matériel protéique utilisé a tout d’abord été analysé une coupure entre les résidus Ala 290 et Gly 291 a été observée au cours de la purification de l'enzyme. Puis, grâce à l'utilisation de techniques spectroscopiques, nous avons cherché à obtenir plus d'informations sur la fixation des substrats/cofacteurs au site actif. Enfin l’étude des mutants et des complexes modèles de l’ACCO a été réalisée afin de mieux comprendre le mécanisme catalytique et de rechercher de nouvelles activités. Nous nous sommes aussi intéressés aux mécanismes d’inactivation de l’ACCO. En présence des effecteurs en excès, cette inactivation se traduit par une fragmentation et une modification de charge. Lorsque la concentration en fer est limitée, aucune modification physique de l’enzyme inactive n’est observée et l'enzyme garde un contenu global en aminoacide et une conformation tridimensionnelle intègres. Des processus oxydatifs se déroulant directement au site actif de l’enzyme sont susceptibles d’engendrer une telle perte d’activité par l'oxydation d'un nombre limité d'acides aminés. Des études en spectrométrie de masse ont été entreprises et sont toujours en cours afin d'identifier les modifications responsables de la perte d'activité de l'enzyme.Enfin nous avons recherché d’éventuelles partenaires protéiques qui pourraient conférer à l’ACCO une meilleure stabilité. Des études préliminaires ont été entreprises et des données de microscopie suggèrent que l'ACCO est localisée près des membranes de la vacuole. / The 1-AminoCyclopropane Carboxylic acid oxidase (ACC Oxidase, ACCO) catalyzes the last step of the biosynthesis of the plant hormone, ethylene. ACCO catalyzes the oxidation of ACC into ethylene in the presence of dioxygen and two electrons (provided in vitro by ascorbate). Carbon dioxide (or bicarbonate ions) are also required for optimum activity. ACCO is an non-heme iron(II) containing enzyme. Given the importance of ethylene in plants, studies on ACCO, as well as on the other enzymes involved in its biosynthesis, have attracted much attention in the past two decades. However, few studies focus on the role of the metal ion and on the catalytic mechanism or the intriguing inactivation processes. ACCO is indeed known for its instability. We first purified and characterised the enzyme. During the purification, a cleavage between residues Ala 290 and Gly 291 was observed. Then, using spectroscopic techniques, we intended to get more information on cofactor's binding in the active site. Finally studies of mutants and model complexes of ACCO were performed in order to get a better understanding of the catalytic mechanism and to look for new activities.We were also interested in the inactivation processes of ACCO. In the presence of an excess of effectors, this inactivation resulted in fragmentation and in pI modification. When the concentration of iron is limited, no modifications of the inactive enzyme were observed. The inactive enzyme maintained its amino acid content and three-dimensional conformation. The loss of activity is therefore likely to derive from oxidative processes directly at the active site. Mass spectrometry experiments were initiated and are still under progress. Finally we were interested in identifying possible protein partners of ACCO that could provide a better stability. Preliminary studies were thus initiated and from microscopy results, ACCO was found located close to the vacuole membrane.

This thesis describes synthetic studies directed towards the total synthesis of the nakafuran and florlide marine natural products. Chapter One provides an overview of the importance of natural products to current medicinal chemistry and describes how the "supply issue" associated with these biologically derived compounds can be resolved through the process of total synthesis. Two families of marine natural products, the nakafurans and the florlides, are introduced as synthetic targets and strategies utilising a type II intramolecular Diels-Alder (IMDA) reaction to achieve their total synthesis are delineated. The efficient preparation of regio- and stereodefined vinyl coupling fragments via hydrostannylation and hydrohalogenation methodology is described in Chapter Two. The palladium-catalysed cross-coupling of these fragments, via Stille or Negishi coupling methodology, yielded dienes which were successfully advanced to IMDA triene precursors. Chapter Three describes investigation of the type II IMDA reaction to give bicyclo[4.3.1]decene carbocyclic skeletons. A facile acid-catalysed 6,7-alkene to 7,8-alkene olefinic isomerisation, via a proposed oxonium intermediate, and the inability to appropriately functionalise the desired adducts impeded progress along the synthetic route. Molecular modelling was conducted to investigate the causes of this unexpected reactivity. Investigations in Chapter Four describe the successful synthesis and cyclisation of homomethyl triene analogues prepared via application of enyne metathesis chemistry. The use of an exo-cyclopropylcarbinyl fragmentation was found to be unsuccessful as a means of installing the desired 6-methyl-bicyclo[4.3.1]decan-2-one core with a competing endo-ring expansion giving rise to a bicyclo[4.4.1]undecane ring system. Chapter 5 summarises the above results and gives a brief discussion of the future potential of this research to provide for a total synthesis of the nakafuran and florlide natural products.

Ce travail est en relation avec la thématique "Chimie Verte" en particulier, le rôle de la catalyse,l’utilisation des matières premières renouvelables et l’élimination des produits nocifs.- Quatre échantillons commerciaux de zircone tungstatée de Mel-Chemicals.- deux séries de zircone tungstatée préparées par deux méthodes différentes avec une teneuren WO3 de 1 à 20 % en masse.- des oxydes binaires tels que WO3-ZrO2, B2O3-ZrO2, Al2O3-ZrO2, Ga2O3-ZrO2 et In2O3-ZrO2.- des oxydes binaires tels que WO3-Me2O3 (Me = B, Al, Ga et In) et finalement des oxydesternaires WO3/(Me2O3-ZrO2) (Me = B, Al, Ga et In) ont été étudiés et préparés lors de cettethèse.La performance catalytique de ces catalyseurs a été évaluée dans l’hydrolyse de la cellobiose, ladéshydratation du fructose et la réduction catalytique sélective des NOx. Les propriétés acides etredox de surface ont été corrélées aux performances catalytiques. En général, la conversion totale est liée à l’acidité des catalyseurs. Les catalyseurs les plus sélectifs pour la déshydratation du fructose et en deNOx sont ceux présentant une acidité modérée. / This work is related to the subject “Green Chemistry” in particular the role of the catalyst, the useof renewable raw materials and the decrease of hazardous materials.- Four commercial tungstated zirconia provided by Mel-Chemicals.- Two series of tungstated zirconia catalysts prepared by two different methods in a range of(1-20) WO3 wt.% loading- Binary zirconia-based oxides WO3-ZrO2, B2O3-ZrO2, Al2O3-ZrO2, Ga2O3-ZrO2 and In2O3-ZrO2.- Binary oxides WO3-Me2O3 (Me = B, Al, Ga and In) and ternary oxides WO3/(Me2O3-ZrO2)(Me = B, Al, Ga and In) were prepared and studied during my PhD thesis.The catalytic activity of these mixed oxide catalysts was evaluated in cellobiose hydrolysis, fructosedehydration and selective catalytic reduction of NOx. The catalysts were thoroughly characterizedin terms of their acidic and redox properties in order to find correlations between the identifiedactive sites and the catalytic properties. The total conversion is related in general to the acidity ofthe tested catalysts and the most selective catalysts for fructose dehydration and deNOx are thosewith moderate acidity.