Les composés de type pyrrocidine sont des polykétides PKS-NRPS possédant des activités biologiques intéressantes comme antifongique ou antibiotique. La synthèse totale de ces composés est un réél challenge comme il est constitué de 10 centres chiraux et d'un macrocycle complexe. L'étude de leur biosynthèse pourrait être d'une aide importante afin de comprendre le mécanisme de formation de cette structure spéciale, et en particulier l'étape de la cyclisation complexe.Le précurseur linéaire de ces polykétides étant composé par une chaine nonakétide (partie PKS) et d'une L-tyrosine (partie NRPS), des hypothèses sur leur biosynthèse ont été émises dans cette thèse. Des expériences d'incorporation de précurseurs marqués ou non vont être réalisées dans différents milieux de culture en vue d'obtenir des informations sur cette biosynthèse, et plus précisément le passage du précurseur linéaire vers la structure polycyclique complexe. En parallèle, des supplémentations des cultures d'A. zeae avec des dérivés de la tyrosine seront faites dans le but d'obtenir des analogues pouvant avoir des activités biologiques nouvelles ou meilleures que les pyrrocidines. / Pyrrocidine and its related compounds are PKS-NRPS polyketides having biological interests such as antifungal or antibiotic activities. The total synthesis of these entities has been challenging since the family of hirsutellone is composed by 10 chiral centers and a complex macrocycle. Studying the biosynthesis of these compounds can be an asset for the comprehension of this special molecular structure, especially for the complex cyclization step. Knowing that the linear precursor of these molecules is constituted by a nonaketide chain (PKS part) and by an L-tyrosine (NRPS part), hypotheses about the biosynthesis of hirsutellone-related compounds have been developed in this thesis. Some incorporation experiments of labeled or unlabeled compounds has been done in different culture media in order to have more information about this biosynthesis, in particular the conversion of the linear precursor into this complex polycyclic structure. In parallel, the supplementation of L-tyrosine derivatives will help us to get some analogs of pyrrocidine which can have new or better activities than natural products.

La propagation des micro-organismes résistants aux antibiotiques menace le système mondial de santé publique. Pour lutter contre ce phénomène, le renouvellement des molécules utilisées en antibiothérapie est devenu une priorité mondiale. Les antibiotiques étant principalement d’origine microbienne, l’étude des micro-organismes et de leurs métabolites s’est donc renforcée et s’oriente vers des écosystèmes peu explorés comme les biotopes marins.Nous avons exploré les activités antimicrobiennes d’une collection de 183 champignons isoles de sédiments marins profonds et collectés entre 4 et 1884 mètres sous le plancher océanique. Le potentiel de production de métabolites de cette collection a été révélé par un criblage génétique ciblant les PolyKetide synthase (PKS), les Non-Ribosomal Peptide Synthetase (NPRS), les TerPene Synthase (TPS) et les hybrides PKS-NRPS. Après avoir regroupé les isolats en fonction de leur profil MSP PCR, 110 ont été sélectionnés pour un criblage fonctionnel, montrant une forte proportion de champignons filamenteux antimicrobiens (32%).Après extraction et fractionnement, les composés bioactifs de 3 souches ont été caractérisés aux niveaux structural et fonctionnel. Ainsi, O. griseum UBOCC-A-114129 produit la fuscine, la dihydrofuscine, la secofuscine et la dihydrosecofuscine, P. bialowiezense UBOCC-A-114097 produit l’acide mycophénolique et Penicillium sp. produit UBOCC-A-114109 la rugulosine.Parallèlement, des analyses en LC-HRMS, réalisées sur des extraits fongiques, ont révélé un grand nombre de métabolites non décrits dans les bases de données. Les champignons des sédiments marins constituent donc un réservoir de structures originales à explorer. / The spreading of antimicrobial resistant microorganisms jeopardizes global health caresystem. To counteract this threat the renewal of antibiotic molecules is a global priority. Antibioticcompounds are mainly originated from microorganisms, so microorganisms and their secondarymetabolites received an increasing interest. The search for new natural antimicrobial compoundsfrom microorganisms gained untapped ecosystems as marine biosphere.We investigated the antimicrobial properties of a fungal collection. The 183 fungal isolateswere collected from deep subseafloor sediment and isolated between 4 and 1,884 meters belowthe seafloor. Secondary metabolites production potential was studied for all isolates in thecollection by screening genes coding PolyKetide Synthase (PKS), Non-Ribosomal Peptide Synthetase(NRPS), TerPene Synthase (TPS) and hybrid PKS-NRPS. After isolates dereplication according to theirMSP-PCR fingerprinting, an antimicrobial screening was performed for 110 isolates, highlighting ahigh proportion of filamentous fungi with antimicrobial properties (32%).After extraction and bio-guided fractionation bioactive metabolites isolated from 3 strains,were characterized in a structural and functional manner: O. griseum UBOCC-A-114129 producedfuscin, dihydrofuscin, secofuscin and dihydrosecofuscine, P. bialowiezense UBOCC-A-114097synthetized mycophenolic acid and Penicillium sp. UBOCC-A-114109 produced rugulosin.In the meantime, LC-HRMS analysis, performed on fungal extracts, showed a great proportionof metabolites not detected in interrogated databases. So, deep subseafloor fungi, represent anuntapped reservoir of original structures to explore.

En 2022, le cancer colorectal (CCR) est le deuxième cancer le plus meurtrier au Canada et le troisième dans le monde. Plusieurs facteurs dont l’alimentation, le manque d'activité physique et la génétique, ont été identifiés comme contribuant au développement du CCR. Le microbiote intestinal, une communauté de micro-organismes vivant dans l'intestin de l'hôte, est également associé au développement du CCR, comme particulièrement Escherichia coli productrice de colibactine. Cette génotoxine induit des réticulations inter brin et cassures double brin (DSBs) de l’ADN dans les cellules de mammifères, entraînant des mutations et un risque élevé de développement du CCR. Nous avons pour objectif de contrôler la prolifération et la production de colibactin de la bactérie pks+ E. coli. Nous avons évalué la prévalence des bactéries pks+ et des bactéries bft+ chez des patients atteints de CCR et individus sains de la province de Québec (Canada), en utilisant une cohorte de 156 participants. Nous avons constaté qu'une grande proportion d’individus sains sont colonisés par des bactéries pks+ (42%) et à des niveaux similaires à ceux des patients atteints de CCR (46%). En ce qui concerne la bactérie entérotoxigénique Bacteroides fragilis (ETBF), le gène bft a été détecté chez 21% des contrôles sains et 32% des patients atteints de CCR, et 8% des contrôles sains et 13% des patients atteints de CRC étaient colonisés à la fois par des bactéries pks+ et par ETBF. Comme ces individus sains sont plus susceptibles de développer un CCR, il est vital de fournir des traitements nutritionnels et médicinaux personnalisés pour contrôler la croissance de ces bactéries. Nous avons ensuite étudié l'effet de la supplémentation en prébiotiques sur la génotoxicité des souches de E. coli productrice de colibactine dans un modèle cellulaire. L'inuline et les galacto-oligosaccharides ont augmenté l'expression du gène de la colibactine A chez E. coli pks+, ce qui a été aboli par l'addition de 125 µM de sulfate de fer. La souche de E. coli NC101 (EcNC101) a augmenté les dysplasies et DSBs dans les cellules d'adénocarcinome humain Caco-2, en présence de l'un ou l'autre des oligosaccharides. 6 Nos résultats indiquent que les oligosaccharides aggravent les dommages à l'ADN causés par les bactéries productrices de colibactine. Étant donné la popularité croissante de la supplémentation en prébiotiques et leur facilité d'accès, d'autres études sont nécessaires pour déterminer comment ces prébiotiques peuvent réguler le développement et la progression des tumeurs dans des modèles animaux et chez les humains en présence d'une colonisation par E. coli pks+. Nous avons constaté précédemment que l'inuline avait à la fois des effets protecteurs et des effets promoteurs de tumeurs dans le CCR, et ces divergences peuvent être attribuées à la présence de E. coli pks+. En utilisant le modèle de souris ApcMin/+ de CCR, nous avons cherché à savoir si les bactéries E. coli productrice de colibactine modifiaient la protection conférée par l'inuline contre le développement et la progression des tumeurs. La supplémentation en inuline a conduit à une augmentation de la colonisation par EcNC101, ce qui a entraîné une élévation des DSBs, de la charge tumorale et de la progression tumorale chez les souris ApcMin/+, de manière dépendante à la colibactine. E. coli Nissle 1917 pasteurisé a inhibé la croissance tumorale en inhibant la prolifération de EcNC101 induite par l'inuline. Nos résultats soulignent la nécessité de dépister les bactéries pks+ chez les patients et de leur fournir des conseils nutritionnels préventifs. En résumé, nous avons rapporté que les pré-biotiques, pro-biotiques et post-biotiques peuvent influencer la croissance de E. coli pks+ et/ou la sécrétion de colibactine. Par conséquent, la pertinence de ce projet serait de fournir une thérapie nutritionnelle personnalisée basée sur ces résultats pour les individus colonisés par ces bactéries, qui sont plus enclins à développer un cancer colorectal. / In 2022, colorectal cancer (CRC) was the second deadliest cancer in Canada and the third globally. Factors such as diet, lack of physical activity, and genetics have been identified as contributors to CRC development. The intestinal microbiota, a community of microorganisms living in the host intestine, has been associated with CRC development, particularly the colibactin-producing Escherichia coli. The genotoxin colibactin induces interstrand cross-links (ICLs) double-strand DNA breaks (DSBs) in mammalian cells, resulting in mutations and an elevated risk of CRC development. Therefore, these studies aimed to control the proliferation and production of colibactin of pks+ E. coli. Using a case-control study of 156 participants, we evaluated the prevalence of pks+ bacteria and bft+ bacteria in patients with CRC and healthy controls from the province of Québec (Canada). We found that similar to patients with CRC (46%), a large proportion of healthy controls were colonized by pks+ bacteria (42%). Regarding enterotoxigenic Bacteroides fragilis (ETBF), the bft gene was observed in 21% of healthy controls and 32% of patients with CRC, with 8% of healthy controls and 13% of patients with CRC colonized by both pks+ bacteria and ETBF. Providing personalized dietary and medicinal treatments to control the growth of these bacteria is necessary because these healthy individuals are more likely to develop CRC. The effect of prebiotic supplementation on the genotoxicity of colibactin-producing E. coli strains was investigated in a cellular model. Inulin and galactooligosaccharide increased the expression of the colibactin A gene in pks+ E. coli, which was abrogated by the addition of 125 µM of iron sulfate. E. coli strain NC101 (EcNC101) increased dysplasia and DSBs breaks in human adenocarcinoma Caco-2 cells, in the presence of both inulin and galactooligosaccharide. Our findings indicate that oligosaccharides aggravate DNA damage caused by colibactin-producing bacteria. 4 Given the increasing popularity and accessibility of prebiotic supplementation, more studies are required to determine how these prebiotics may regulate tumor development and progression in animal models and humans in the presence of pks+ E. coli colonization. Inulin has protective and tumor-promoting effects on CRC; these discrepancies may be attributed to the presence of pks+ E. coli. Using the ApcMin/+ mouse model of CRC, we explored whether colibactin-producing E. coli altered the protection conferred by inulin against tumor development and progression. Inulin supplementation increased EcNC101 colonization, resulting in more DSBs, tumor burden, and tumor progression in ApcMin/+ mice, in a colibactin dependant manner. Pasteurized E. coli Nissle 1917 inhibited tumor growth by reversing inulin-driven EcNC101 proliferation. Our findings emphasized the need to screen patients for pks+ bacteria and provide them with preventive dietary counseling. In summary, we reported that prebiotics, probiotics, and postbiotics could influence pks+ E. coli growth, colibactin secretion, or both. Therefore, the significance of this project lies in providing personalized nutritional-based therapy based on the findings for individuals colonized by these bacteria, who are more prone to develop CRC.

This Master thesis deals with the design of linear unit with hydraulic actuator for the robot with parallel kinematic structure. One of the objectives is to get an overview of the differences related to characteristics of design and construction between serial and parallel kinematic structure (PKS) of the industrial robots, as a new type of technical objects in robotics. In addition the aim is to create an original structural design of linear unit, as the basic constructional assembly and operational node of robot with PKS, according to the specified input values, such as power, pressure, speed and stroke, important for the design of linear hydraulic actuator.

O estudo fitoquímico de Peperomia oreophila revelou a presençca de duas lignanas furofurânicas (7R, 8R, 7R, 8R)-3,4,5-trimetóxi-3,4-metilenodioxi-5-metóxi- 8.8,7.O.9,7.O.9-lignana (1), (7R, 8R, 7R, 8R)-3,4,5-trimetóxi-3,4,5-trimetóxi- 8.8,7.O.9,7.O.9-lignana (2); as duas amidas (2E)-N-isobutil-3-(5-metóxi-7,8- benzodioxol-1-il)acrilamida (3), (2E)-N-isobutil-3-(3,4,5-trimetóxifenil)acrilamida (4), três derivados de acido cinâmico (2E)-3-(3,4,5-trimetóxifenil)acrilato de metila (5), (2Z)-3- (3,4,5-trimetóxifenil)acrilato de metila (6), (2E)-3-(5-metóxi-7,8-benzodioxol-1-il)acrilato de metila (7); os dois policetídeos fenólicos [(2E)-3,7-dimetilocta-2,6-dien-1-il]-5- metil-2-(3-metilbut-2-en-1-il)benzeno-1,3-diol (8) (inédita) e [(2E)-3,7-dimetilocta- 2,6-dien-1-il]-2,2,7-trimetil-2H-cromen-5-ol (9); de P. arifolia: o policetídeo fenólico [(2E)-3,7-dimetilocta-2,6-dien-1-il]-5-metil-2-(3-metilbut-2-en-1-il) benzeno-1,3-diol, isolada também de P. oreophila (10) (inédita); de P. urocarpa: o policetídeo fenólico 5- metil-2-[(2E,6E)-3,7,11-trimetildodeca-2,6,10-trien-1-il] benzeno-1,3-diol (11) e o ácido 2,4-dihidróxi-6-metil-3-[(2E,6E)-3,7,11-trimetildodeca-2,6,10-trien-1-il] benzóico, (12); de P. nitida: o fenilpropanoide apiol (1-alil-3,6-dimetóxi-10,11- benzodioxol) (13), os cromenos 7-hidróxi-2,2,5-trimetil-2H-cromeno-carboxilato de metila (14) e o 7-metóxi-2,2,5-dimetil-2H-cromeno-6-carboxilato de metila (15). O policetídeo 2-hidróxi-4,6-dimetóxiacetofenona, principal metabólito das folhas de P. glabella, teve sua biossíntese investigada utilizando-se como precursores o acetil-CoA e o malonil-CoA. Foram realizados estudos de otimização da atividade de policetídeo sintase (PKS) em função do pH, tempo de reação, temperatura e saturação de substratos, além de estudos da variação circadiana. Estudos de genes de PKS resultaram em amplificações cujo seqüenciamento poderá determinar a identidade dessas regiões e homologia entre as seqüências dessas Peperomias e a região KS do gene AviM de Streptomyces viridochromogenes que expressa o ácido orselínico / The phytochemical investigation carried out on Peperomia oreophila revealed the accumulation of two furofuran lignans (7R,8R,7R,8R)-3,4,5-trimethoxy-3,4- methylenedioxy-8.8, 7.O.9, 9.O.7-lignan (1), (7, 8R, 7R, 8)-3,4,5-trimethoxy-3,4,5- trimethoxy-8.8-7.O.9, 9.O.7-lignan (2); two amides (2´E)-N-isobutyl-3´-(5-methoxy-7,8- benzodioxol-1-yl) acrylamide (3), (2E)-N-isobutyl-3-(3,4,5-trimethoxyphenyl)acrylamide (4), three derivate cinâmic acid methyl (2E)-3-(3,4,5-trimethoxyphenyl)acrylate (5), methyl (2Z)-3-(3,4,5-trimethoxyphenyl)acrylate (6), methyl (2E)-3-(5-methoxy-7,8- benzodioxol-1-yl)acrylate (7); two phenolic polyketides [(2E)-3,7-dimethylocta-2,6- dien-1-yl]-5-methyl-2-(3-methylbut-2-en-1-yl)benzene-1,3-diol (8) (novel), [(2´E)-3´,7´- dimethylocta-2´,6´-dien-1-yl]-2,2,7-trimethyl-2H-chromen-5-ol (9); P. arifolia, two phenolic polyketide [(2E)-3,7-dimethylocta-2,6-dien-1-yl]-5-methyl-2-(3-methylbut-2- en-1-yl)benzene-1,3-diol, also isolated from P. oreophila (10) (novel); P. urocarpa, the two phenolic polyketides 5-methyl-2-[(2E,6E)-3,7,11-trimethyldodeca-2,6,10-trien-1- yl]benzene-1,3-diol (11) and 2,4-dihydroxy-6-methyl-3-[(2E,6E)-3,7,11-trimethyldodeca- 2,6,10-trien-1-yl]benzoic acid (12); P. nitida, the phenylpropanoid apiole 1-allyl-3,6- dimethoxy-10,11-benzodioxole (13); the chromenes methyl 7-hydroxy-2,2,5-trimethyl- 2H-chromene-6-carboxylate (14) and methyl 7-methoxy-2,2,5-trimethyl-2H-chromene-6- carboxylate (15). The polyketide 2-hydroxy-4,6-dimethoxyacetophenone, the major compound in P. glabella leaves, had its biosynthetic origin investigated using acetyl-CoA and malonyl-CoA as precursors. The enzymatic activity of polyketide synthase was optimized to pH, incubation time, temperatures and substrate saturation, in addition to the analysis of circadian variation activity. The amplifications of putative PKS genes was based on primers from AviM gene of Streptomyces viridochromogenes that express for orsellinic acid. The sequencing will enable the identification of such regions and also to study the homology to fungi PKS

Modular polyketide synthases (PKSs) are the largest enzymes known to man and are responsible for synthesizing some of the most important human medicines. Their ability to construct stereochemically-rich carbon chains containing diverse substituents has inspired the biosynthetic community to engineer these factories for the in vitro synthesis of a small library of polyketide compounds. New complex polyketides are discovered every year, yet the lack of compound prohibits characterization and testing of these new compounds for medicinal properties. Smaller polyketide compounds generated in vitro could be organically manipulated to generate larger, more complex polyketide natural products and natural product analogs. Chemoenzymatic approaches like this would be extremely beneficial to the scientific community; however, there are still obstacles that must be overcome before the use of PKS for the preparative synthesis of an in vitro generated polyketide library would prove fruitful: purchasing substrates such as methylmalonyl-CoA is cost-prohibitive, PKSs are often difficult to express and purify, and the products generated are typically nonchromophoric. The use of a malonyl-CoA ligase from Streptomyces coelicolor (MatB) was investigated for the enzymatic synthesis of polyketide extender units such as methylmalonyl-CoA (Chapter 2). MatB synthesized a total of 5 CoA-linked extender units in vitro: malonyl-, methylmalonyl-, ethylmalonyl-, hydroxymalonyl- and methoxymalonyl-CoA. Two ternary complex structures of MatB with bound product and leaving group were also solved to sub-2Å resolution. MatB generated extender units were employed in the module-catalyzed synthesis of a triketide pyrone. The selectivity of a PKS module to incorporate a variety of side chains into triketide pyrones was also investigated (Chapter 3). A total of 10 triketide pyrone compounds were synthesized, 5 produced via modular "stuttering" and one possessing a terminal alkyne chemical handle. Lastly, nonchromphoric polyketide products were made visible upon copper(I)-catalyzed azide alkyne cycloaddition (CuAAC) with fluorescent sulforhodamine B azide revealing insights into in vitro reactivites of a PKS module (Chapter 4). The work described in this dissertation has helped advance the scientific community towards procuring an in vitro synthesized polyketide library for future synthetic applications. / text

Some of the most interesting objects in the Universe are Active Galactic Nuclei. In the centre of an active galaxy is a supermassive black hole that accretes matter from the surrounding galaxy. In the process, not yet fully understood, some of the matter is ejected in two jets, perpendicular to the plane of the galaxy. The energy of the particles in the jets are extremely high, sometimes over 1019 eV. The features of an active galaxy can be very different depending on from which angle it is viewed. This means that some astronomical objects that earlier seemed to be very heterogeneous might be only different manifestations of the same type of object, namely active galactic nuclei. This thesis introduces some of these different objects. The unifying theory is described. Ways of detecting the high-energy radiation and two important instruments, H.E.S.S. and Fermi-LAT are described. Three studies of the BL Lac PKS 2155-304, an active galactic nucleus that points its jet almost straight at Earth, are made using Fermi-LAT data. The conclusion of the studies is that the source is variable at least in the time scale of days and that in order to gather further information about these objects simultaneous multi-wavelength surveys have to be done.

O estudo fitoquímico de Peperomia oreophila revelou a presençca de duas lignanas furofurânicas (7R, 8R, 7R, 8R)-3,4,5-trimetóxi-3,4-metilenodioxi-5-metóxi- 8.8,7.O.9,7.O.9-lignana (1), (7R, 8R, 7R, 8R)-3,4,5-trimetóxi-3,4,5-trimetóxi- 8.8,7.O.9,7.O.9-lignana (2); as duas amidas (2E)-N-isobutil-3-(5-metóxi-7,8- benzodioxol-1-il)acrilamida (3), (2E)-N-isobutil-3-(3,4,5-trimetóxifenil)acrilamida (4), três derivados de acido cinâmico (2E)-3-(3,4,5-trimetóxifenil)acrilato de metila (5), (2Z)-3- (3,4,5-trimetóxifenil)acrilato de metila (6), (2E)-3-(5-metóxi-7,8-benzodioxol-1-il)acrilato de metila (7); os dois policetídeos fenólicos [(2E)-3,7-dimetilocta-2,6-dien-1-il]-5- metil-2-(3-metilbut-2-en-1-il)benzeno-1,3-diol (8) (inédita) e [(2E)-3,7-dimetilocta- 2,6-dien-1-il]-2,2,7-trimetil-2H-cromen-5-ol (9); de P. arifolia: o policetídeo fenólico [(2E)-3,7-dimetilocta-2,6-dien-1-il]-5-metil-2-(3-metilbut-2-en-1-il) benzeno-1,3-diol, isolada também de P. oreophila (10) (inédita); de P. urocarpa: o policetídeo fenólico 5- metil-2-[(2E,6E)-3,7,11-trimetildodeca-2,6,10-trien-1-il] benzeno-1,3-diol (11) e o ácido 2,4-dihidróxi-6-metil-3-[(2E,6E)-3,7,11-trimetildodeca-2,6,10-trien-1-il] benzóico, (12); de P. nitida: o fenilpropanoide apiol (1-alil-3,6-dimetóxi-10,11- benzodioxol) (13), os cromenos 7-hidróxi-2,2,5-trimetil-2H-cromeno-carboxilato de metila (14) e o 7-metóxi-2,2,5-dimetil-2H-cromeno-6-carboxilato de metila (15). O policetídeo 2-hidróxi-4,6-dimetóxiacetofenona, principal metabólito das folhas de P. glabella, teve sua biossíntese investigada utilizando-se como precursores o acetil-CoA e o malonil-CoA. Foram realizados estudos de otimização da atividade de policetídeo sintase (PKS) em função do pH, tempo de reação, temperatura e saturação de substratos, além de estudos da variação circadiana. Estudos de genes de PKS resultaram em amplificações cujo seqüenciamento poderá determinar a identidade dessas regiões e homologia entre as seqüências dessas Peperomias e a região KS do gene AviM de Streptomyces viridochromogenes que expressa o ácido orselínico / The phytochemical investigation carried out on Peperomia oreophila revealed the accumulation of two furofuran lignans (7R,8R,7R,8R)-3,4,5-trimethoxy-3,4- methylenedioxy-8.8, 7.O.9, 9.O.7-lignan (1), (7, 8R, 7R, 8)-3,4,5-trimethoxy-3,4,5- trimethoxy-8.8-7.O.9, 9.O.7-lignan (2); two amides (2´E)-N-isobutyl-3´-(5-methoxy-7,8- benzodioxol-1-yl) acrylamide (3), (2E)-N-isobutyl-3-(3,4,5-trimethoxyphenyl)acrylamide (4), three derivate cinâmic acid methyl (2E)-3-(3,4,5-trimethoxyphenyl)acrylate (5), methyl (2Z)-3-(3,4,5-trimethoxyphenyl)acrylate (6), methyl (2E)-3-(5-methoxy-7,8- benzodioxol-1-yl)acrylate (7); two phenolic polyketides [(2E)-3,7-dimethylocta-2,6- dien-1-yl]-5-methyl-2-(3-methylbut-2-en-1-yl)benzene-1,3-diol (8) (novel), [(2´E)-3´,7´- dimethylocta-2´,6´-dien-1-yl]-2,2,7-trimethyl-2H-chromen-5-ol (9); P. arifolia, two phenolic polyketide [(2E)-3,7-dimethylocta-2,6-dien-1-yl]-5-methyl-2-(3-methylbut-2- en-1-yl)benzene-1,3-diol, also isolated from P. oreophila (10) (novel); P. urocarpa, the two phenolic polyketides 5-methyl-2-[(2E,6E)-3,7,11-trimethyldodeca-2,6,10-trien-1- yl]benzene-1,3-diol (11) and 2,4-dihydroxy-6-methyl-3-[(2E,6E)-3,7,11-trimethyldodeca- 2,6,10-trien-1-yl]benzoic acid (12); P. nitida, the phenylpropanoid apiole 1-allyl-3,6- dimethoxy-10,11-benzodioxole (13); the chromenes methyl 7-hydroxy-2,2,5-trimethyl- 2H-chromene-6-carboxylate (14) and methyl 7-methoxy-2,2,5-trimethyl-2H-chromene-6- carboxylate (15). The polyketide 2-hydroxy-4,6-dimethoxyacetophenone, the major compound in P. glabella leaves, had its biosynthetic origin investigated using acetyl-CoA and malonyl-CoA as precursors. The enzymatic activity of polyketide synthase was optimized to pH, incubation time, temperatures and substrate saturation, in addition to the analysis of circadian variation activity. The amplifications of putative PKS genes was based on primers from AviM gene of Streptomyces viridochromogenes that express for orsellinic acid. The sequencing will enable the identification of such regions and also to study the homology to fungi PKS

We present Chandra and XMM-Newton X-ray, Very Large Array (VLA) radio, and optical observations of three candidate compact steep spectrum (CSS) radio galaxies. CSS sources are of a galactic scale and are presumably driving a shock through the interstellar medium (ISM) of their host galaxy. B3 1445+410 is a low-excitation emission line CSS radio galaxy with possibly a hybrid Fanaroff-Riley FRI/II (or fat double) radio morphology. The Chandra observations reveal a point-like source that is well fit with a power law consistent with the emission from a Doppler boosted core. 3C 268.3 is a CSS broad-line radio galaxy (BLRG) whose Chandra data are consistent spatially with a point source centered on the nucleus and spectrally with a double power-law model. PKS B1017-325 is a low-excitation emission line radio galaxy with a bent double radio morphology. While from our new spectroscopic redshift, PKS B1017-325 falls outside the formal definition of a CSS, the XMM-Newton observations are consistent with ISM emission with either a contribution from hot shocked gas or non-thermal jet emission. We compile selected radio and X-ray properties of the nine bona fide CSS radio galaxies with X-ray detections so far. We find that two out of the nine show X-ray spectroscopic evidence for hot shocked gas. We note that the counts in the sources are low and that the properties of the two sources with evidence for hot shocked gas are typical of the other CSS radio galaxies. We suggest that hot shocked gas may be typical of CSS radio galaxies due to their propagation through their host galaxies.

No description available.