Evolution of the rbcS gene family in Solanaceae: concerted evolution and gain and loss of introns, with a description of new statistical guidelines for determining the number of unique gene copies.

Thesis (Ph.D.)--University of Washington, 2014

Deciphering the mechanisms underlying the loss of BDNF neuroprotection in an Alzheimer’s disease model

Tese de mestrado, Neurociências, Faculdade de Medicina, Universidade de Lisboa, 2016

Managing sales people strategically when promoting new products: Incorporating market orientation into a sales management control framework

Salespeople play a pivotal role in promoting new products. Therefore, managers need to know what control mechanism (i.e., output-based control, behavior-based control, or knowledge-based control) can improve their salespeople's new product sales performance. Furthermore, managers may be able to assist salespeople in performing better by having a strong market orientation. The literature has been inconsistent regarding the effects of sales management control mechanisms and has not yet incorporated market orientation into a sales management control framework. The current study surveyed 315 Taiwanese salespeople from publicly traded electronics companies with the aim of contributing to the sales management literature. The results show that sales management controls can directly affect salespeople's innovativeness, which, in turn, affects new product sales performance. However, sales management controls cannot affect performance directly. Furthermore, market orientation can positively moderate the relationship between salespeople's innovativeness and new product sales performance.

Protein deiminases: new players in the developmentally regulated loss of neural regenerative ability

Spinal cord regenerative ability is lost with development, but the mechanisms underlying this loss are still poorly understood. In chick embryos, effective regeneration does not occur after E13, when spinal cord injury induces extensive apoptotic response and tissue damage. As initial experiments showed that treatment with a calcium chelator after spinal cord injury reduced apoptosis and cavitation, we hypothesized that developmentally regulated mediators of calcium-dependent processes in secondary injury response may contribute to loss of regenerative ability. To this purpose we screened for such changes in chick spinal cords at stages of development permissive (E11) and non-permissive (E15) for regeneration. Among the developmentally regulated calcium-dependent proteins identified was PAD3, a member of the peptidylarginine deiminase (PAD) enzyme family that converts protein arginine residues to citrulline, a process known as deimination or citrullination. This post-translational modification has not been previously associated with response to injury. Following injury, PAD3 up-regulation was greater in spinal cords injured at E15 than at E11. Consistent with these differences in gene expression, deimination was more extensive at the non-regenerating stage, E15, both in the gray and white matter. As deimination paralleled the extent of apoptosis, we investigated the effect of blocking PAD activity on cell death and deiminated-histone 3, one of the PAD targets we identified by mass-spectrometry analysis of spinal cord deiminated proteins. Treatment with the PAD inhibitor, Cl-amidine, reduced the abundance of deiminated-histone 3, consistent with inhibition of PAD activity, and significantly reduced apoptosis and tissue loss following injury at E15. Altogether, our findings identify PADs and deimination as developmentally regulated modulators of secondary injury response, and suggest that PADs might be valuable therapeutic targets for spinal cord injury.

Network mechanisms of intentional learning

The ability to learn new tasks rapidly is a prominent characteristic of human behaviour. This ability relies on flex- ible cognitive systems that adapt in order to encode temporary programs for processing non-automated tasks. Previous functional imaging studies have revealed distinct roles for the lateral frontal cortices (LFCs) and the ven- tral striatum in intentional learning processes. However, the human LFCs are complex; they house multiple dis- tinct sub-regions, each of which co-activates with a different functional network. It remains unclear how these LFC networks differ in their functions and how they coordinate with each other, and the ventral striatum, to support intentional learning. Here, we apply a suite of fMRI connectivity methods to determine how LFC networks activate and interact at different stages of two novel tasks, in which arbitrary stimulus-response rules are learnt either from explicit instruction or by trial-and-error. We report that the networks activate en masse and in synchrony when novel rules are being learnt from instruction. However, these networks are not homogeneous in their functions; instead, the directed connectivities between them vary asymmetrically across the learning timecourse and they disengage from the task sequentially along a rostro-caudal axis. Furthermore, when negative feedback indicates the need to switch to alternative stimulus–response rules, there is additional input to the LFC networks from the ventral striatum. These results support the hypotheses that LFC networks interact as a hierarchical system during intentional learning and that signals from the ventral striatum have a driving influence on this system when the internal program for processing the task is updated.

A new approach for multi-agent coalition formation and management in the scope of electricity markets

This paper presents a new methodology for the creation and management of coalitions in Electricity Markets. This approach is tested using the multi-agent market simulator MASCEM, taking advantage of its ability to provide the means to model and simulate VPP (Virtual Power Producers). VPPs are represented as coalitions of agents, with the capability of negotiating both in the market, and internally, with their members, in order to combine and manage their individual specific characteristics and goals, with the strategy and objectives of the VPP itself. The new features include the development of particular individual facilitators to manage the communications amongst the members of each coalition independently from the rest of the simulation, and also the mechanisms for the classification of the agents that are candidates to join the coalition. In addition, a global study on the results of the Iberian Electricity Market is performed, to compare and analyze different approaches for defining consistent and adequate strategies to integrate into the agents of MASCEM. This, combined with the application of learning and prediction techniques provide the agents with the ability to learn and adapt themselves, by adjusting their actions to the continued evolving states of the world they are playing in.

New roles of Rab GTPases on eye diseases: targeting VEGF secretion

RESUMO: A retina é composta, entre outras estruturas, pelo epitélio pigmentar da retina (EPR)e pela coróide. A região central da retina denomina-se mácula, e é a zona mais afetada na degenerescência macular relacionada com a idade, a forma mais comum de degenerescência da retina. Nesta doença, a secreção de fatores de crescimento pelo EPR é afetada, nomeadamente a do fator de crescimento vascular endotelial (VEGF), e pouco se sabe ainda sobre os mecanismos moleculares conducentes a esta condição. A família de proteínas Rab GTPases está envolvida nas vias intracelulares de sinalização e tráfego membranares, essenciais na transdução de sinais extracelulares em respostas biológicas. A sua crucial importância nestes mecanismos levou-nos a considerar o seu potencial envolvimento nas vias de secreção do VEGF, e a questionar-nos se teriam algum papel regulador sobre as mesmas. O principal objetivo deste trabalho é identificar Rab GTPases importantes para as vias de secreção e endocitose do VEGF no EPR. Essa identificação ajudará a esclarecer a patogénese da degenerescência macular da retina, e poderá servir para uma procura mais direcionada de novos agentes terapêuticos. A caracterização de dois modelos in vitro do EPR, células primárias isoladas de murganho e a linha celular B6-RPE07,levou-nos a concluir que são ambos semelhantes. Contudo, a linha celular foi escolhida como protótipo do EPR por permitir o acesso a um número ilimitado de células. No decurso deste trabalho, desenvolvemos e caracterizámos uma biblioteca de ferramentas moleculares que nos permitiram reduzir os níveis proteicos das proteínas Rab GTPases, com base na tecnologia de ácido ribonucleico (ARN) de interferência. O papel das proteínas Rab GTPases na secreção do VEGF no EPR foi estudado com base no silenciamento de apenas uma proteína, ou combinando várias, segundo a sua localização e funções intracelulares descritas. Este trabalho permitiu-nos concluir que as proteínas Rab GTPases são importantes intervenientes no processo de secreção de VEGF pelo EPR, e confirmar dados anteriores que relatam o envolvimento de algumas Rab GTPases endocíticas no processo. Propomos ainda um novo modelo para a interação destas proteínas no EPR, e sugerimos que a Rab10 e a Rab14 atuam negativamente sobre a Rab8, controlando o seu funcionamento. Os nossos resultados evidenciam a importância das proteínas Rab GTPases na secreção do VEGF pelas células do EPR, e servem de base a futuros estudos que melhor procurem compreender este mecanismo e de que modo a sua alteração se relaciona com a degenerescência da retina.--------ABSTRACT: Retinal pigment epithelium (RPE) and choroid are components of the mammalian retina, of which the central region is called macula. The most common form of retinaldegeneration, age-related macular degeneration (AMD), involves primarily deregulation of growth factors secretion by the RPE. Very little is known about the molecular mechanisms that lead to impairment of RPE’s homeostatic intracellular processes, namely the secretion of vascular endothelial growth factor (VEGF). Rab GTPases’ family regulates membrane targeting and traffic, being essential in the transduction of signal pathways. Given Rab proteins’ role in intracellular trafficking, we propose to identify key regulatory Rab proteins involved in either the secretory or the recycling pathways of VEGF in RPE. Understanding how Rab proteins’ function disruption could lead to retinal and choroidal pathology would ultimately contribute to find new therapeutic agents. Here, we characterized two mouse RPE in vitro cell models, primary cells and B6-RPE07 cell line, and concluded that both display important epithelial features as the RPE presents in vivo. Considering unlimited cell number and results reproducibility, we chose B6-RPE07 cells to further study Rab proteins’ function. To scrutinize the consequences of Rab proteins’ absence or diminished levels, we have developed novel molecular tools to achieve silencing of these key proteins using miRNA technology. We further addressed the effect of Rab proteins’ absence on VEGF secretion by performing an extensive screening where different Rab proteins were silenced, both individually and in multiple combinations considering their cellular/ compartment location. We conclude that Rab GTPases are important intervenients in VEGF secretion by RPE cells, confirming endocytic Rab proteins’ role in regulation of VEGF biology. We also propose a novel model for Rab proteins’ interaction in RPE. Our results suggest that Rab10 and Rab14 might influence Rab8 in a negative feedback mechanism, important for controlling VEGF secretion. Our achievements’ unravel Rab proteins’ role in VEGF secretion by RPE cells and are the basis for future studies to better understand RPE molecular secretory machinery.

Exploring ionic liquids′ unique stimuli to elucidate uncharacterised cellular and molecular mechanisms in filamentous fungi

The emergence of new fungal pathogens, either of plants or animals, and the increasing number of reported cases of resistant human pathogenic strains to the available antifungal drugs reinforces the need for better understanding the biology of filamentous fungi. Conventional drugs target components of the fungal membrane or cell wall, therefore identifying novel intracellular targets, yet unique to fungi, is a global priority.(...)

A new selective peroxisome proliferator-activated receptor gamma antagonist with antiobesity and antidiabetic activity.

Peroxisome proliferator-activated receptor gamma (PPAR-gamma) plays a key role in adipocyte differentiation and insulin sensitivity. Its synthetic ligands, the thiazolidinediones (TZD), are used as insulin sensitizers in the treatment of type 2 diabetes. These compounds induce both adipocyte differentiation in cell culture models and promote weight gain in rodents and humans. Here, we report on the identification of a new synthetic PPARgamma antagonist, the phosphonophosphate SR-202, which inhibits both TZD-stimulated recruitment of the coactivator steroid receptor coactivator-1 and TZD-induced transcriptional activity of the receptor. In cell culture, SR-202 efficiently antagonizes hormone- and TZD-induced adipocyte differentiation. In vivo, decreasing PPARgamma activity, either by treatment with SR-202 or by invalidation of one allele of the PPARgamma gene, leads to a reduction of both high fat diet-induced adipocyte hypertrophy and insulin resistance. These effects are accompanied by a smaller size of the adipocytes and a reduction of TNFalpha and leptin secretion. Treatment with SR-202 also dramatically improves insulin sensitivity in the diabetic ob/ob mice. Thus, although we cannot exclude that its actions involve additional signaling mechanisms, SR-202 represents a new selective PPARgamma antagonist that is effective both in vitro and in vivo. Because it yields both antiobesity and antidiabetic effects, SR-202 may be a lead for new compounds to be used in the treatment of obesity and type 2 diabetes.

Cellular source and mechanisms of high transcriptome complexity in the Mammalian testis.

Understanding the extent of genomic transcription and its functional relevance is a central goal in genomics research. However, detailed genome-wide investigations of transcriptome complexity in major mammalian organs have been scarce. Here, using extensive RNA-seq data, we show that transcription of the genome is substantially more widespread in the testis than in other organs across representative mammals. Furthermore, we reveal that meiotic spermatocytes and especially postmeiotic round spermatids have remarkably diverse transcriptomes, which explains the high transcriptome complexity of the testis as a whole. The widespread transcriptional activity in spermatocytes and spermatids encompasses protein-coding and long noncoding RNA genes but also poorly conserves intergenic sequences, suggesting that it may not be of immediate functional relevance. Rather, our analyses of genome-wide epigenetic data suggest that this prevalent transcription, which most likely promoted the birth of new genes during evolution, is facilitated by an overall permissive chromatin in these germ cells that results from extensive chromatin remodeling.

Creatine deficiency syndomes : a new model of partial GAMT deficiency affecting brain cell development

Les syndromes de déficiences cérébrales en créatine (CCDS) sont dus à des mutations dans les gènes GATM et G AMT (codant pour les enzymes AGAT et G AMT de la voie de synthèse de créatine) ainsi que SLC6A8 (transporteur de créatine), et génèrent une absence ou une très forte baisse de créatine (Cr) dans le cerveau, mesurée par spectroscopic de résonance magnétique. Les patients CCDS développent des handicaps neurologiques sévères. Les patients AGAT et GAMT peuvent être traités avec des doses importantes de Cr, mais gardent dans la plupart des cas des séquelles neurologiques irréversibles. Aucun traitement efficace n'existe à ce jour pour la déficience en SLC6A8. Bien que de nombreux modèles aient été développés pour comprendre la Cr cérébrale en conditions physiologiques, les pathomécanismes des CCDS ne sont pas encore compris. Des souris transgéniques pour les gènes Gatm, Gamt et Slc6a8 ont été générées, mais elles ne miment que partiellement la pathologie humaine. Parmi les CCDS, la déficience en GAMT est la plus sévère, en raison de l'accumulation cérébrale de l'intermédiaire guanidinoacétate (GAA). Alors que la toxicité cérébrale du GAA a été étudiée par exposition directe au GAA d'animaux adultes sains, les mécanismes de la toxicité du GAA en condition de déficience en GAMT dans le cerveau en développement sont encore inconnus. Le but de ce projet était donc de développer un modèle de déficience en GAMT dans des cultures 3D primaires de cellules nerveuses de rat en agrégats par knock-down du gène GAMT, en utilisant un virus adéno-associé (AAV) induisant le mécanisme d'interférence à l'ARN (RNAi). Le virus scAAV2, à la multiplicité d'infection de 1000, s'est révélé le plus efficace pour transduire tous les types de cellules nerveuses des cultures (neurones, astrocytes, oligodendrocytes), et générer un knock-down maximal de la protéine GAMT de 85% (jour in vitro 18). Cette déficience partielle en GAMT s'est révélée insuffisante pour générer une déficience en Cr, mais a causé l'accumulation attendue de GAA, à des doses comparables aux niveaux observés dans le LCR des patients GAMT. Le GAA a induit une croissance axonale anarchique accompagnée d'une baisse de l'apoptose naturelle, suivis par une induction tardive de mort cellulaire non-apoptotique. Le co-traitement par la Cr a prévenu tous les effets toxiques du GAA. Ce travail montre que l'accumulation de GAA en absence de déficience en Cr est suffisante pour affecter le développement du tissu nerveux, et suggère que des formes de déficiences en GAMT supplémentaires, ne présentant pas de déficiences en Cr, pourraient être découvertes par mesure du GAA, en particulier à travers les programmes récemment proposés de dépistage néonatal de la déficience en GAMT. -- Cerebral creatine deficiency syndromes (CCDS) are caused by mutations in the genes GATM and GAMT (respectively coding for the two enzymes of the creatine synthetic pathway, AGAT and GAMT) as well as SLC6A8 (creatine transporter), and lead to the absence or very strong decrease of creatine (Cr) in the brain when measured by magnetic resonance spectroscopy. Affected patients show severe neurological impairments. While AGAT and GAMT deficient patients can be treated with high dosages of Cr, most remain with irreversible brain sequelae. No treatment has been successful so far for SLC6A8 deficiency. While many models have helped understanding the cerebral Cr pathways in physiological conditions, the pathomechanisms underlying CCDS are yet to be elucidated. Transgenic mice carrying mutations in the Gatm, Gamt and Slc6a8 genes have been developed, but only partially mimic the human pathology. Among CCDS, GAMT deficiency is the most severe, due to the CNS accumulation of the guanidinoacetate (GAA) intermediate. While brain toxicity of GAA has been explored through direct GAA exposure of adult healthy animals, the mechanisms underlying GAA toxicity in GAMT deficiency conditions on the developing CNS are yet unknown. The aim of this project was thus to develop and characterize a GAMT deficiency model in developing brain cells by gene knockdown, by adeno-associated virus (AAV)-driven RNA interference (RNAi) in rat 3D organotypic primary brain cell cultures in aggregates. scAAV2 with a multiplicity of infection of 1000 was shown as the most efficient serotype, was able to transduce all brain cell types (neurons, astrocytes, oligodendrocytes) and to induce a maximal GAMT protein knockdown of 85% (day in vitro 18). Metabolite analysis showed that partial GAMT knockdown was insufficient to induce Cr deficiency but generated the awaited GAA accumulation at concentrations comparable to the levels observed in cerebrospinal fluid of GAMT-deficient patients. Accumulated GAA induced axonal hypersprouting paralleled with inhibition of natural apoptosis, followed by a later induction in non-apoptotic cell death. Cr supplementation led to the prevention of all GAA-induced toxic effects. This work shows that GAA accumulation without Cr deficiency is sufficient to affect CNS development, and suggests that additional partial GAMT deficiencies, which may not show the classical brain Cr deficiency, may be discovered through GAA measurement including by recently proposed neonatal screening programs for GAMT deficiency.

Mechanisms of protein homeostasis in health, aging and disease.

When emerging from the ribosomes, new polypeptides need to fold properly, eventually translocate, and then assemble into stable, yet functionally flexible complexes. During their lifetime, native proteins are often exposed to stresses that can partially unfold and convert them into stably misfolded and aggregated species, which can in turn cause cellular damage and propagate to other cells. In animal cells, especially in aged neurons, toxic aggregates may accumulate, induce cell death and lead to tissue degeneration via different mechanisms, such as apoptosis as in Parkinson's and Alzheimer's diseases and aging in general. The main cellular mechanisms effectively controlling protein homeostasis in youth and healthy adulthood are: (1) the molecular chaperones, acting as aggregate unfolding and refolding enzymes, (2) the chaperone-gated proteases, acting as aggregate unfolding and degrading enzymes, (3) the aggresomes, acting as aggregate compacting machineries, and (4) the autophagosomes, acting as aggregate degrading organelles. For unclear reasons, these cellular defences become gradually incapacitated with age, leading to the onset of degenerative diseases. Understanding these mechanisms and the reasons for their incapacitation in late adulthood is key to the design of new therapies against the progression of aging, degenerative diseases and cancers.

New threats - old routines : bureaucratic adaptability in the security policy environment

Within the framework of state security policy, the focus of this dissertation are the relations between how new security threats are perceived and the policy planning and bureaucratic implementation that are designed to address them. In addition, this thesis explores and studies some of the inertias that might exist in the core of the state apparatus as it addresses new threats and how these could be better managed. The dissertation is built on five thematic and interrelated articles highlighting different aspects of when new significant national security threats are detected by different governments until the threats on the policy planning side translate into protective measures within the society. The timeline differs widely between different countries and some key aspects of this process are also studied. One focus concerns mechanisms for adaptability within the Intelligence Community, another on the policy planning process within the Cabinet Offices/National Security Councils and the third focus is on the planning process and how policy is implemented within the bureaucracy. The issue of policy transfer is also analysed, revealing that there is some imitation of innovation within governmental structures and policies, for example within the field of cyber defence. The main findings of the dissertation are that this context has built-in inertias and bureaucratic seams found in most government bureaucratic machineries. As much of the information and planning measures imply security classification of the transparency and internal debate on these issues, alternative assessments become limited. To remedy this situation, the thesis recommends ways to improve the decision-making system in order to streamline the processes involved in making these decisions. Another special focus of the thesis concerns the role of the public policy think tanks in the United States as an instrument of change in the country’s national security decision-making environment, which is viewed from the perspective as being a possible source of new ideas and innovation. The findings in this part are based on unique interviews data on how think tanks become successful and influence the policy debate in a country such as the United States. It appears clearly that in countries such as the United States think tanks smooth the decision making processes, and that this model with some adaptations also might be transferrable to other democratic countries.

Biogeochemistry of Paleozoic brachiopods from New York State and Ontario

A comprehensive elemental, isotopic and microstructural analyses was undertaken of brachiopod calcites from the Hamilton Group (Middle Devonian), Clinton Group (Middle Silurian) and Middle to Upper Ordovician strata of Ontario and New York State. The majority of specimens were microstructurally and chemically preserved in a pristine state, although a number of specimens show some degree of post-depositional alteration. Brachiopod calcites from the Hamilton and Clinton Groups were altered by marine derived waters whereas Trenton Group (Middle Ordovician) brachiopods altered in meteorically derived fluids. Analysis of the elemental and isotopic compositions of pristine Hamilton Group brachiopods indicates there are several chemical relationships inherent to brachiopod calcite. Taxonomic differentiation of Mg, Sr and Na contents was evident in three co-occuring species from the Hamilton Group. Mean Mg contents of pristine brachiopods were respectively Athyris spiriferoides (1309ppm), Mucrospirifer mucronatus (1035ppm) and Mediospirifer audacula (789ppm). Similarly, taxonomic differentiation of shell calcite compositions was observed in co-occuring brachiopods from the Clinton Group (Middle Silurian) and the Trenton Group (Middle Ordovician). The taxonomic control of elemental regulation into shell calcite is probably related to the slightly different physiological systems and secretory mechanisms. A relationship was observed in Hamilton Group species between the depth of respective brachiopod communities and their Mg, Sr and Na contents. These elements were depleted in the shell calcites of deeper brachiopods compared to their counterparts in shallower reaches. Apparently shell calcite elemental composition is related to environmental conditions of the depositional setting, which may have controlled the secretory regime, mineral morphology of shell calcite and precipitation rates of each species. Despite the change in Mg, Sr and Na contents between beds and formations in response to environmental conditions, the taxonomic differentiation of shell calcite composition is maintained. Thus, it may be possible to predict relative depth changes in paleoenvironmental reconstructions using brachiopod calcite. This relationship of brachiopod chemistry to depth was also tested within a transgressiveregressive (T-R) cycle in the Rochester Shale Formation (Middle Silurian). Decreasing Mg, Sr and Na contents were observed in the transition from the shallow carbonates of the Irondequoit Formation to the deeper shales of the lowest 2 m of Rochester Shale. However, no isotopic and elemental trends were observed within the entire T-R cycle which suggests that either the water conditions did not change significantly or that the cycle is illusory. A similar relationship was observed between the Fe and Mn chemistries of shell calcite and redox/paleo-oxygen conditions. Hamilton Group brachiopods analysed from deeper areas of the shelf are enriched in Mn and Fe relative to those from shallow zones. The presence of black shales and dysaerobic faunas, during deposition of the Hamilton Group, suggests that the waters of the northern Appalachian Basin were stratified. The deeper brachiopods were marginally positioned above an oxycline and their shell calcites reflect periodic incursions of oxygen depleted water. Furthermore, analysis of Dalmanella from the black shales of the Collingwood Shale (Upper Ordovician) in comparison to those from the carbonates of the Verulam Formation (Middle Ordovician) confirm the relationship of Fe and Mn contents to periodic but not permanent incursions of low oxygen waters. The isotopic compositions of brachiopod calcite found in Hamilton Group (813C; +2.5% 0 to +5.5% 0; 8180 -2.50/00 to -4.00/00) and Clinton Group (813C; +4.00/00 to +6.0; 8180; -1.8% 0 to -3.60/ 00) are heavier than previously reported. Uncorrected paleotemperatures (assuming normal salinity, 0% 0 SMOW and no fractionation effects) derived from these isotopic values suggest that the Clinton sea temperature (Middle Silurian) ranged from 18°C to 28°C and Hamilton seas (Middle Devonian) ranged between 24°C and 29°C. In addition, the isotopic variation of brachiopod shell calcite is significant and is related to environmental conditions. Within a single time-correlative shell bed (the Demissa Bed; Hamilton Group) a positive isotopic shift of 2-2.5% 0 in 013C compositions and a positive shift of 1.0-1.50/00 in 0180 composition of shell calcite is observed, corresponding with a deepening of brachiopod habitats toward the axis of the Appalachian Basin. Moroever, a faunal succession from deeper Ambocoelia dominated brachiopod association to a shallow Tropidoleptus dominated assocation is reflected by isotopic shifts of 1.0-1.50/00. Although, other studies have emphasized the significance of ±20/oo shifts in brachiopod isotopic compositions, the recognition of isotopic variability in brachiopod calcite within single beds and within depositional settings such as the Appalachian Basin has important implications for the interpretation of secular isotopic trends. A significant proportion of the variation observed isotopic distribution during the Paleozoic is related to environmental conditions within the depositional setting.

Reactions of some non-enolisable chloroketones with amide ion and a new synthesis of acridones /|nGuo-shyoung John Chen. -- 260 St. Catharines, Ont. : [s. n.],

This research was directed mainly towards the investigation of the reacti.ons of· substituted chlorobenziophenones under strongly basi,c conditions. The work 'can be divided into two main sections. The Introduction deals mainly with historical studies on aryne chemistry and the Haller-Bauer reaction. Secti.on I i.s concerned with syntheses of 2-benzamido-2'chlorobenzophenone and 2-benzamido~3'-chlorobenzophenone,and with thei,r respective reactions wi.th potassium amide in ammonia. o-Chlorophenylacetic acid was converted to the acid chloride and then by Friedel-Craftsreaction with benzene to w-(o-chlorophenyl)acetophenone. Reaction wi.th phenylhydrazine and Fischer cyclization gave 3- (0chlorophenyl)- 2-phenylindole, which was ozonized to 2-benzamido-2'chlorobenzophenone. The isomeric 3' -chlor,..o ke: tone was similarly synthesised from m-chlorophenylacetic acid. Both the 2'- and 3' -ch.loroketones gave N-benzoylacridone on treatment with potassium amide in ammonia; an aryne mechanism is involved for the 3'-chloroketone but aryne and nucleophilic substitution mechanisms are possible for the 2'-chloroketone. Hydrolysis of the 2'- and 3'-chloroketones gave 2-amino-2'chlorobenzophenone and 2-amino-3'-chlorobenzophenone respectively. A second new acridone synthesis is given in the Appendix involving reactions of these two ketones with potassium t-butoxide in t-butylbenzene. i Section 2 deals with the investigation of the reaction of some tricyclic ch1orobenzophenones with potassium amide in liquid ammonia. These were 1-ch1orof1uorenone; which was pr~pared in several steps from f1uoranthene, and 1- and 2-ch1oroanthraquinones. 1-Ch1orof1uorenone gave 1-aminof1uorenone ; 1-ch1oroanthraquinone gave 1- and 2-aminoanthraquinones; 2-ch1oroanthraquinone was largely recovered from the attempted reaction.