Le genre Eryngium L. (Apiaceae, Saniculoideae) comprend plus de 250 espèces utilisées en médecine traditionnelle à travers le monde. En Tunisie il existe seulement huit espèces : E. barrelieri Boiss., E. campestre L., E. dichotomum Desf., E. glomeratum Lamk., E. ilicifolium Lamk., E. maritimum L., E. tricuspidatum L. et E. triquetrum Vahl. ; ces espèces sont en majorité peu étudiées du point de vue phytochimique. La présente étude a été effectuée sur la totalité des Eryngium qui poussent en Tunisie dans le but d’évaluer leurs activités biologiques, essentiellement antimicrobienne contre des microorganismes multirésistants et producteurs de béta-lactamases à spectres étendus (BLSE), mais aussi phototoxique et cytotoxique ainsi que la variabilité chimique par analyse par GC-FID et GC-MS des extraits les plus actifs.Toutes les espèces étudiées étaient dotées d’un pouvoir antimicrobien (1,25 à 0,07 mg/mL) et cytotoxique (24,4 à 0,32 µg/mL) considérable. Le criblage de l’activité phototoxique a permis de mettre en évidence la richesse de ces plantes en composés photoréactifs antimicrobiens potentiellement intéressants pour leur efficacité d’action et l’élargissement du spectre d’activité antimicrobienne.L’analyse des extraits actifs apolaires a permis d’étudier la variabilité chimique entre les différentes espèces et la mise en évidence de la présence majoritaire de composés antimicrobiens notamment des sesquiterpènes oxygénés tels que le spathulénol, le lédol, l’α-bisabolol et le cubénol, et des sesquiterpènes hydrocarbonés comme le β-bisabolène et le copaène ; et cytotoxiques tel que le falcarinol.Une étude phytochimique approfondie a été réalisée sur les racines d’E. triquetrum afin d’extraire, isoler par des essais bio-guidés et identifier les composés actifs. Le fractionnement a été optimisé par des chromatographies sur colonnes, CPC et CLHP. Parmi les composés identifiés deux polyacétylènes, le panaxydiol et le falcarinol, ont montré un fort pouvoir antimicrobien et une spécificité d’action notamment contre les souches de Pseudomonas aeruginosa BLSE et multirésistantes, avec des CMI allant jusqu’à 0,25 ng/mL et une activité en majorité bactéricide. / The genus Eryngium L., (Apiaceae, Saniculoideae) comprises more than 250 flowering plant species, which are commonly used as medicinal plants in different countries. Only eight species are growing in Tunisia: E. barrelieri Boiss., E. campestre L., E. dichotomum Desf., E. glomeratum Lamk., E. ilicifolium Lamk., E. maritimum L., E. tricuspidatum L. et E. triquetrum Vahl. These species are used in traditional medicine and there are relatively few papers on the phytochemical investigations of most of them. This study was performed on all Eryngium species growing in Tunisia in order to evaluate their chemical variability using GC-FID and GC-MS analyses and their biological activities, mainly antimicrobial against multiresistant microorganisms and extended spectrum beta-lactamase producing bacteria (ESBL), and also phototoxic and cytotoxic effects.All investigated species showed considerable antimicrobial effect with MIC value ranging between 1,25 and 0,07 mg/mL and important cytotoxic activity against J774 tumoral cells with IC50 from 24,4 to 0,32 µg/mL. Phototoxic investigation demonstrated a significant photoactive inhibitory effects against tested pathogenic microorganisms.GC–MS analysis of the most active crude extracts (petroleum ether extracts) revealed their high content of antimicrobial agents particularly oxygenated sesquiterpenes such as spathulenol, ledol, α-bisabolol and cubenol, and hydrocarbon sesquiterpenes such as β-bisabolene and copaene; and cytotoxic components such as falcarinol.The chemical investigation and bio-guided isolation of active compounds of the selected crude extract of E. triquetrum roots were performed using column chromatography, centrifugal partition chromatography (CPC) and preparative high-performance liquid chromatography (HPLC). among purified components, two bioactive polyacetylenes, panaxydiol and falcarinol, showed a great antimicrobial activity mainly against multiresistant and ESBL producing Pseudomonas aeruginosa with MIC value up to 0,25 ng/ml and a mostly bactericidal effect.

Indiana University-Purdue University Indianapolis (IUPUI) / Polyacetylenic natural products, compounds containing multiple carbon-carbon triple bonds, have been found in a large collection of organisms. Radiochemical tracer studies have indicated that these bioactive metabolites are synthesized from fatty acid precursors through a series of uncharacterized desaturation and acetylenation steps. To date, there are three main pathways believed to be involved in acetylenic natural product biosynthesis. However, it is apparent that the crepenynic acid pathway is the origin of a vast majority of the known plant and fungal acetylenic products. This investigation provides concrete evidence that the polyacetylenic natural products found in the fungus Fistulina hepatica and the medicinal plant species Echinacea purpurea are biosynthesized from crepenynic acid. Through heterologous expression in Yarrowia lipolytica, two acetylenases capable of producing crepenynic acid were identified from E. purpurea. Furthermore, heterologous expression of two diverged desaturases isolated from F. hepatica, uncovered a ∆12-acetylenase and the first multifunctional enzyme capable of ∆14-/∆16- desaturation and ∆14-acetylenation.

Poly(1,4-diethynylbenzene) ( -conjugated polymer) was prepared as an insoluble polymer network via chain coordination polymerization of 1,4-diethynylbezene catalyzed with [Rh(NBD)acac] complex. Thermodynamic properties and acid-base characteristics of the prepared poly(1,4-diethynylbenzene) were studied by means of Inverse Gas Chromatography (IGC) in the temperature range 80-100 řC. Retention data of selected testing substances were used to determine the Gibbs energy of sorption, the sorption enthalpy and their acid-base and disperse parts as well as the disperse contribution to the surface energy and parameters of KA, KD, ANHPS and DNHPS quantifying the acid-base character of the studied polymer. The results showed that poly(1,4-diethynylbenzene) interacted more efficiently with Lewis bases than with Lewis acids. The values of experimental sorption enthalpy were used for the determination of the parameters KA and KD. Values of these parameters classify poly(1,4-diethynylbenzene) as the material with a slightly acid character. This conclusion is further supported by the results of H. P. Schreiber method based on the application of ANHPS and DNHPS parameters for the evaluation of the acid-base properties of the material. The infrared spectroscopy proved that poly(1,4-diethynylbenzene) contained...

The following monoethynylated N-benzylidene-2-hydroxyanilines were prepared: N-(4- ethynylbenzylidene)-2-hydroxyaniline, N-(3-ethynylbenzylidene)-2-hydroxyaniline, N-(4- ethynylbenzylidene)-2-hydroxy-5-nitroaniline and N-(3-ethynylbenzylidene)-2-hydroxy-5- nitroaniline, which differed in the position of the ethynyl group on the benzylidene ring and the substitution of the hydroxyaniline ring. Monoethynylated N-benzylidene-2- hydroxyanilines were used as the monomers for the chain-growth coordination homo- and copolymerization. The homopolymerization resulted in linear polyacetylene homopolymers with N-benzylidene-2-hydroxyaniline substituents. The copolymerization with multiethynylarene-type cross-linkers provided densely cross-linked copolymeric polyacetylene networks. The linear units of the networks carried N-benzylidene-2- hydroxyaniline substituents, the interconnection between the chains of the networks being realized by arene links. The texture parameters of the prepared networks significantly depended on the type of comonomers used. The highest specific surface area values (~530 m2 /g) were achieved with networks prepared by copolymerization of N-(4- ethynylbenzylidene)-2-hydroxyaniline or N-(3-ethynylbenzylidene)-2-hydroxyaniline,with 4,4'-diethynylbiphenyl used as a cross-linker. Selected...

A new type of organometallic polymer networks with a covalent structure of cross-linked substituted polyacetylenes containing Cu2+ or Pd2+ ions (5 to 17 wt%) has been developed. The metal ions were complexed in the networks predominantly with two N-salicylideneaniline ligands covalently bound to two different network monomeric units. Due to the chosen method of complexation, the metal ions have actively participated (as knots of the network) in the formation of cross-linked architecture of the products. For the preparation of organometallic networks two independent methods were used: (i) the direct polymerization of organometallic monomers and (ii) the two-stage method using postpolymerization introduction of metal ions into polyacetylene polymers containing covalently bound N-salicylideneaniline proligands. The starting low-molecular-weight blocks used for the network synthesis were new substances prepared within the framework of the diploma thesis, namely monomers of the mono- and diethynylated N-salicylideneanilines type and diethynylated organometallic monomers in which two molecules of a monoethynylated N-salicylideneaniline complexed one Mt2+ ion. The ethynylated monomers were polymerized to organometallic networks or precursors of these networks via chain-growth coordination polymerization,...

The preparation of a new group of functionalized conjugated polymer networks has been described based on spontaneous quaternization polymerization of ethynylpyridines with bis(bromomethyl)arenes. The networks consisted of polyacetylene chains with pyridyl and pyridiniumyl pendants cross-linked with -CH2(arylene)CH2- links. The variation of the ratio of monomer and quaternization agent in the feed modified the ratio of pyridyl and pyridiniumyl groups in the networks (pyridyl/pyridiniumyl ratios from 0 to 1.32). The networks did not exhibit a permanent microporosity that could be confirmed by nitrogen adsorption at 77 K. Nevertheless, all networks were active in capture of CO2 at 293 K (up to 0.73 mmol CO2/g, 750 Torr). It has been hypothesized that CO2 capture reflected formation of a temporary porous texture of the networks through conformational changes of the network segments enabled by the segments mobility at room temperature. The preparation of functionalized conjugated polymer networks with permanent micro/mesoporosity (SBET up to 667 m2 /g) has been described that was based on chain coordination copolymerization of acetylenic monomers. The copolymerization of 1,4-diethynylbenzene or 4,4'-diethynylbiphenyl with mono or diethynylbenzenes bearing NO2 or CH2OH groups has been demonstrated as...

(Doctoral Thesis, 2016, Mgr. Tomáš Faukner, IONIC POLYACETYLENE TYPE POLYMERS AND POLYMER NETWORKS BY CATALYST FREE QUATERNIZATION POLYMERIZATION) The composition and structure of a series of ionic π-conjugated poly(monosubstituted acetylene)s prepared via catalyst-free quaternization polymerization (QP) of 2-ethynylpyridine (2EP) activated with equimolar amount of alkyl halide [RX = ethyl bromide, ethyl iodide, nonyl bromide and haxadecyl (cetyl) bromide] as a quaternizing agent (QA) have been studied in detail. The performed QPs gave ionic polymers well soluble in polar solvents, with approximately half of pyridine rings quaternized, which implies that also non-quaternized monomers were involved in the process of QP. The configurational structure of polyacetylene main chains was suggested based on 1 H NMR, IR as well as Raman (SERS) spectral methods. The QPs in bulk gave more expected irregular cis/trans polymers while the QPs in acetonitrile solution gave high-cis polymers. A series of prepared symmetrical bi-pyridylacetylene based monomers has been polymerized via QP approach resulting into a series of new ionic π-conjugated poly(disubstituted acetylene) type materials. It is therefore obvious that the mechanism of quaternization activation frequently applied on monosubstituted...

4 ABSTRACT The synthesis has been described yielding a new type of rigid conjugated polymer networks which possess a high content of permanent micropores and macropores and exhibit high surface areas up to 1469 m2/g. The networks have been prepared via chain-growth coordination polymerization catalysed with insertion catalysts based on Rh complexes. This polymerization has been newly applied to bifunctional acetylenic monomers of diethynylarene type (1,4-diethynylbenzene, 1,3-diethynylbenzene and 4,4'-diethynylbiphenyl). The covalent structure of the networks consists of the polyacetylene main chains densely connected by arylene struts. The W and Mo metathesis catalysts have been revealed as inefficient for the synthesis of these networks. The increase in the polymerization temperature and time has been shown to affect positively the content and the diameter (up to 22 nm) of the mesopores in the networks. A mechanism has been proposed that explains the mesopores formation as a result of mutual knitting of small particles of the microporous polymer. The application of emulsion polymerization technique allowed to prepare texturally hierarchical polyacetylene networks possessing interconnected open macropores (diameter up to 4,8 μm) the walls of which exhibited micro/mesoporous texture. It was demonstrated...