The syntheses and properties of various cyclophanes have been extensively investigated by Cram and others. The paracyclophanes are compounds in which benzene rings are linked to each other by two saturated chains at the para positions, as in structure I. When they are joined to the meta positions, they are called metacyclophanes.

The first chapter of this thesis deals with the synthesis, cyclisation of 2-aminobenzophenones and biomimetic synthesis of acridone alkaloids. The biogenesis of acridone alkaloids produced in tissue culture is described. 2,4,6-Triacetoxy-2'-methylaminobenzophenone was prepared to study its cyclisation to the acridone ring system. 2,4,6-Triacetoxy-2'-methylaminobenzophenone was converted to 1,3-dihydroxy-N-methylacridone. The intermediate 2,4,6-trihydroxy-2'-methylaminobenzophenone was also synthesised and found to be highly reactive, cyclising extremely easily to the acridone thus confirming the probable role of the 2'-aminobenzophenone as a precursor in the biosynthesis of acridone alkaloids in tissue cultures. The second part is concerned with a phytochemical investigation of two species of <i>Ruta</i> namely <i>Ruta montana</i> and <i>Ruta chalepensis</i> from Turkey. This chapter deals with the isolation and identification of coumarins and alkaloids from both species of <i>Ruta</i>. The compounds which are isolated and identified from root extracts of <i>Ruta montana</i> are chalepensin, rutamarin, xanthotoxin and marmesin. From the root extract of <i>Ruta chalepensis</i> the alkaloid skimmianine was isolated together with chalepensin, rutamarin, and bargapten. An as yet, unidentified sugar was isolated. The structures of these natural products were elucidated on the basis of spectroscopic data together with comparisons with published data and authentic samples (wherever possible).

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Since only one example of an asymmetric synthesis which involved an intermediate containing an optically active ligand has been reported, two questions immediately arise: "Is this type of asymmetric synthesis an isolated example, or is it a stepping stone toward a generalized trend for Co (III) which may be extended to include levo rotatory, as well as dextro rotatory molecules?" In addition, asymmetric synthesis affords a new avenue for synthesizing resolved neutral complexes.

Morphine and its derivatives continue to challenge the creativity of synthetic chemists. The aim of this research is to execute a short chiral synthesis of the morphinan system. Chirality is introduced via asymmetric reduction; the key step is the formation of four rings- the tetracyclic phenanthrofuran by an intramolecular Diels-Alder cycloaddition. The fifth ring was completed by three different methods, and three different pentahydrophenanthrofuran systems were obtained.

Morphine and its derivatives continue to challenge the creativity of synthetic chemists. The aim of this research is to execute a short chiral synthesis of the morphinan system. Chirality is introduced via asymmetric reduction; the key step is the formation of four rings- the tetracyclic phenanthrofuran by an intramolecular Diels-Alder cycloaddition. The fifth ring was completed by three different methods, and three different pentahydrophenanthrofuran systems were obtained.

The synthesis of o-(N,N-dimethylamino)methylphenyl tris (trimethylsilyl) silane (II), a photochemical precursor of o- (N,N-dimethylamino) methylphenyl (trimethylsilyl) sila ammonium ylide (intramolecular silylene complex) and otolyl(trimethylsilyl)silylene is reported. Photolysis of II at room temperature in a cyclohexane solution of triethyl silane produced the silylene ylide and the presumably uncomplexed isomer, a silylene, which is trapped to afford the 2-(o-(N,N-dimethylamino)methylphenyl) -1,1,1-triethyl 3,3,3-trimethyltrisilane, 33% yield. A second decomposition pathway, a photodeamination, produced o-tris(trimethyl silyl) silyltoluene. UV spectra of the silaammonium ylide formed in the photochemical reaction of II was observed at 77k in hard or soft matrices.

>Magister Scientiae - MSc / This thesis reports on the syntheses of complexes of (arene) ruthenium (II) isoniazid Schiff base ligands for antimicrobial studies. Isoniazid Schiff base ligands; isonicotinyl acid (2-hydroxy-5- methyl-benzilidene)-hydrazide (L1), isonicotinyl acid (2-hydroxy-5-methoxy-benzilidene)- hydrazide (L2), isonicotinyl acid (-5-chloro-2-hydroxy-benzilidene)-hydrazide (L3), isonicotinyl acid (-5-bromo-2-hydroxy-benzilidene)-hydrazide (L4), isonicotinyl acid (2-hydroxy-5-nitrobenzilidene)- hydrazide (L5) were prepared by condensation reaction under reflux from equimolar amounts of isioniazid, which is an amine, with five different aldehyde moieties. Ruthenium (II) complexes of these isoniazid Schiff base ligands (C1 - C5) were prepared in an ethanolic solution under reflux and inert atmosphere at 60°C using Schlenk techniques. Fourier transform infrared spectroscopy (FTIR), ultraviolet – visible spectroscopy, thermogravimetric analysis, nuclear magnetic resonance and elemental analysis were the characterization techniques that confirmed the successful preparation of the ligands. All the ligands spectra displayed the imine functional group peak which confirmed the successful preparation. The ligands L1 – L5 and the complexes C1 – C5 were subjected to similar characterization techniques which further confirmed the successful syntheses and the coordination of metal and ligand by displaying a shift in their respective imine peaks and transitions values. All the synthesized compounds were subjected to a standard antimicrobial test using three microorganisms, Staphylococcus aureus, Methicillin resistant Staphylococcus aureus and Pseudomonas aeruginosa. Out the ten compounds tested, only ligand L5 gave the best results against Staphylococcus aureus.

PhD thesis assessing the role of non-randomized studies with randomized in evidence syntheses of health interventions. / Randomized studies (RS) are considered the best source of evidence for knowledge syntheses (e.g., systematic reviews, health technology assessments, health guidelines, among others) about healthcare interventions. Historically, non-randomized studies (NRS) have been usually discarded from knowledge syntheses of interventions due to their intrinsic risk of bias and confounding, and they are used only when RS are considered unfeasible or unethical to conduct. With better research methods in observational studies and new tools for the evaluation of risk of bias, NRS are more likely to be a helpful source of information when used as replacement, sequential, or complementary evidence. This, together with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, provide an opportunity for guiding decisions about using RS and NRS in knowledge synthesis and increasing our certainty in a body of evidence. This work aims to improve research synthesis methods by assessing the role and use of RS and NRS in knowledge syntheses using GRADE. This can help health professionals, researchers, guideline developers, and policy-makers build better and more complete healthcare recommendations. / Thesis / Doctor of Philosophy (PhD) / All recommendations about healthcare interventions (from common medicines to strategies to prevent diseases) should ideally come from an adequate synthesis (e.g., systematic reviews) of the least biased studies. Many researchers and authors of health syntheses consider randomized studies (RS), the ‘gold standard’ to demonstrate if an intervention is truly effective. Unfortunately, they are not always available, feasible, or ethical to conduct. Non-randomized studies (NRS), also called observational studies, can potentially provide complementary evidence for a research question. Unfortunately, they are usually considered of poorer quality because of their intrinsic nature of being prone to bias and confounding. In most circumstances, authors of syntheses discard these types of studies from the outset, without considering their potential for providing evidence that could complement or even replace that from randomized studies. This work aims to improve this situation by offering methods for evaluating the appropriateness of integrating both RS and NRS, guiding authors and researchers in cases where this is possible, hence increasing the certainty in a body of evidence and help all stakeholders reach decisions.

Orientador: Maria Del Pilar Taboada Sotomayor / Banca: Luis Francisco Moreira Gonçalves / Banca Débora Gonçalves / Resumo: O desenvolvimento de métodos analíticos cada vez mais seletivos e sensíveis é de grande importância para uma melhor qualidade na determinação de espécies químicas, aumentando assim a confiabilidade dos resultados obtidos. Com isso, o emprego e otimização das etapas de separação/concentração se faz necessário. O emprego de polímeros molecularmente impressos (do inglês - "Molecularly Imprinted Polymers" - MIP) tem demonstrado ser uma eficiente ferramenta analítica com grande potencialidade para minimizar as limitações das técnicas de separação/concentração tradicionalmente empregadas. No caso deste trabalho, o template utilizado será o valerato de estradiol, principalmente pela sua importância inerente na reposição hormonal feminina e por se tratar de um disruptor endócrino (hormônio) lançado ao meio ambiente sem nenhum controle. Assim a síntese do polímero para identificação do valerato de estradiol foi realizada por diferentes rotas (bulk e precipitação) através de duas vias de polimerização (termopolimerização e fotopolimerização) variando o monômero funcional (MAA, acrilonitrila, 2-vinil-piridina e 1-vinilimidazol). O MIP e NIP foram colocados, um de cada vez, em sistema soxhlet contendo metanol/ácido acético na proporção 70/30 a 60º C, para remoção da molécula impressa, através de cinco lavagens sucessivas em períodos de 24 h. Essas águas de lavagem foram analisadas utilizando espectrofotometria UV/Vis. Posteriormente com os parâmetros otimizados o polímero que apresentou ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The development of selective and sensitive analytical methods has significant importance for an improvement at determination of chemical species; increasing the reliability of the results obtained. So, the use and optimization of separation and concentration steps is necessary. The use of Molecularly Imprinted Polymers (MIP) has been shown to be an efficient analytical tool with great potential to minimize the limitations of separation/concentration techniques traditionally employed. In the case of this study, the template used will be estradiol valerate, once of its inherent importance in female hormone replacement and because it is an endocrine disruptor (hormone) released into the environment without any control. Thus, the synthesis of the polymer for the identification of estradiol valerate was performed by different routes (bulk and precipitation) through two polymerization techniques (thermopolymerization and photopolymerization) by varying the functional monomer (MAA, acrylonitrile, 2-vinyl pyridine and 1- vinylimidazole). MIP and NIP were placed in a soxhlet system containing 70/30 methanol/acetic acid at 60 ° C for removal of the imprinted molecule through five successive washes in 24 h periods. These wash waters were analyzed using UV/Vis spectrophotometry. Subsequently, with the optimized parameters, the polymer that presented the best result was modified with magnetic nanoparticles (core@shell); being synthesized magnetic MIP (MMIP) for estradiol valerate, increas... (Complete abstract click electronic access below) / Mestre