Utilização da berberina na identificação dos mastócitos do molusco Anomalocardia brasiliana

Berberine is an alkaloid used as a fluorochrome in the identification of heparin and DNA. Enerback, 1974, described the technique used until today to study granules rich in heparin of vertebrate mast cells. Santos et al., 2003, studied mast cells of the mollusk Anomalocardia brasiliana using biochemical and histological analysis. This work used the fluorescent dye berberine technique to improve characterization of these cells. Mollusk organs (ctenidium and mantle) were processed with routine histological techniques. Tissue sections were treated with berberine 0,02% in redistilled water acidified to pH 4, by the addition of citric acid for 20 minutes. The visualization was made through fluorescence microscopy with ultraviolet region emission. The mast cell fluorescence had a strong yellow color, where cell nuclei appeared more greenish. This result was very similar to the ones reported before. Mast cells are location at the epithelium surface is the same in both organs, mantle and ctenidium. The fluorescence was easily observed in the granules. Therefore, this technique showed to be good and sensitive to study mast cell of invertebrates

HETEROSIS AND HERITABILITY ESTIMATES OF PURINE ALKALOIDS AND POLYPHENOLS IN COCOA

Cocoa ( Theobroma cacao L. ) is an important allogamous tropical tree crop, whose centre of diversity is considered to be in Central America. Dry cocoa beans from five cocoa clones, and their intercrossed hybrids were analysed based on the variation of alkaloids and polyphenolic compounds contents, in order to gain insights on the heterosis and broad-sense heritability. Polyphenols and alkaloids were analysed at 280 nm by HPLC, using a Photodiode Array Detector (PDA); while anthocyanins were separated with the SEP-PAK Vac 6cc 1000 mg (waters) column and measured at 520 nm with a PDA. Dry cocoa beans displayed high content of purine alkaloids (2.1 and 8.8 mg g-1 for caffein and theobromine, respectively), and polyphenols (25 and 2978 µg g-1 for catechin and epicatechin, respectively). Among the five cocoa clones, SNK16 was the highest in purine alkaloid (caffein and theobromin) and flavanol (catechin and epicatechin); while T79/467 possessed the greatest quantity of cyanidin-3-galactoside and cyanidin-3-arabinoside. From all the parameters studied, anthocyanins (Cyanidin-3-galactoside and cyanidin-3-arabinoside) exhibited the highest level of heterosis. Parental genotypes SNK16 and T79/467 showed good aptitudes for the combination of characters because their reciprocal hybrids F5 and F9, distinguished themselves by better levels of mid-parent heterosis values. Besides, the heritability value in strict sense of this Cyanidin-3-galactoside was very high. Absence of significant difference between genotypes, coming from reciprocal crossbreeding for Cyanidin-3-galactoside, suggests that this character in cocoa would be nuclear contrary to purine alkaloids and flavan-3-ols, where their transmission to offsprings can be stated as cytoplasmic.

Development of an organocatalytic method for the enantioselective synthesis of rivastigmine

The focus of this thesis was the study of a recently developed class of picolinamide cinchona alkaloid derivatives for the synthesis of Rivastigmine, a biologically active compound used for the treatment of Alzheimer’s disease. Six 9-picolinamide-cinchona alkaloid derivatives were successfully synthesized through simple and effective methods. These catalysts were then applied in the enantioselective reduction of O-protected ketimines (intermediates of Rivastigmine). The hydrosilylation of the N-phenyl ketimines afforded good results with excellent yields and high enantioselectivities, while much lower values, in terms of both enantioselectivity and yield, were obtained in the reduction of N-benzyl ketimines. Preliminary studies on the immobilization of these organocatalysts to different solid supports were conducted, with the purpose of applying them in continuous flow systems, which to date has never been reported; RESUMO: No âmbito deste trabalho, foi estudada a síntese de um composto biologicamente ativo usado para o tratamento da doença de Alzheimer, Rivastigmina, usando uma classe de picolinamidas derivadas de alcaloides de cinchona recentemente desenvolvida. Seis 9-picolinamida derivados de alcaloides de cinchona foram preparados com êxito através de metodologias simples e eficazes. Os organocatalisadores foram posteriormente aplicados na redução enantiosseletiva de cetiminas O-protegidas (intermediários de Rivastigmina). Foram obtidos bons resultados na hidrossililação de N-fenilo cetiminas, com rendimentos excelentes e elevadas enantiosseletividades, enquanto a redução de N-benzilo cetiminas proporcionou valores muito mais baixos, tanto em termos de rendimento como de enantiosseletividade. Com o objetivo de serem aplicados em sistemas de fluxo contínuo, realizaram-se estudos preliminares sobre a imobilização destes organocatalisadores em diferentes suportes sólidos, a qual, ate à data, ainda não foi descrita na literatura.

I. Synthetic Studies Toward the Total Synthesis of Polycyclic Natural Products – Communesin F, Perophoramidine and Ineleganolide. II. Nickel Catalyzed Intramolecular C–O Bond Formation

Expedient synthetic approaches to the highly functionalized polycyclic alkaloids communesin F and perophoramidine are described using a unified approach featuring a key decarboxylative allylic alkylation to access a crucial and highly congested 3,3-disubstituted oxindole. Described are two distinct, stereoselective alkylations that produce structures in divergent diastereomeric series possessing the critical vicinal all-carbon quaternary centers needed for each synthesis. Synthetic studies toward these challenging core structures have revealed a number of unanticipated modes of reactivity inherent to these complex alkaloid scaffolds. Finally, a previously unknown mild and efficient deprotection protocol for the o-nitrobenzyl group is disclosed – this serendipitous discovery permitted a concise endgame for the formal syntheses of both communesin F and perophoramidine.

In addition, the atroposelective synthesis of PINAP ligands has been accomplished via a palladium-catalyzed C–P coupling process through dynamic kinetic resolution. These catalytic conditions allow access to a wide variety of alkoxy- and benzyloxy-substituted PINAP ligands in high enantiomeric excess.

An efficient and exceptionally mild intramolecular nickel-catalyzed carbon–oxygen bond-forming reaction between vinyl halides and primary, secondary, and tertiary alcohols has been achieved. This operationally simple method allows direct access to cyclic vinyl ethers in high yields in a single step.

Finally, synthetic studies toward polycyclic ineleganolide are described. The entire fragmented carbon framework has been constructed from this work. Highly (Z)-selective olefination was achieved by the method by the Ando group.

Desenvolvimento de uma nanoformulação autoemulsificante contendo o alcaloide epiisopiloturina para melhorar sua biodisponibilidade plasmática após administração via oral

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Nanociência e Nanobiotecnologia, 2016.