Programa de Pós-Graduação em Ciências Farmacêuticas - PPGCF/ICS
URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/2312
O Programa de Pós-Graduação em Ciências Farmacêuticas (PPGCF) vinculado ao Instituto de Ciências da Saúde (ICS) da Universidade Federal do Pará (UFPA) apresenta um auto-impacto de inserção regional uma vez que se trata do único PPGCF na Região Norte pelo grande potencial de utilização da biodiversidade na região amazônica. Além de favorecer a fixação e atração de profissionais qualificados na área de Ciências Farmacêuticas na Região Amazônica.
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Item Acesso aberto (Open Access) Estudo do mecanismo do nitrofeniletano na prostaglandina-endoperóxido sintase e relação estrutura-propriedade de nitroderivados(Universidade Federal do Pará, 2011-08-17) VALE, Joyce Karen Lima; SOUZA, Perjentino José da Cunha; http://lattes.cnpq.br/9909053957915090; BORGES, Rosivaldo dos Santos; http://lattes.cnpq.br/4783661132100859Previous studies suggest that the essential oil of Aniba canelilla containing high levels of 1-nitro-2-phenylethane has antinociceptive activity, anti-inflammatory and hypotensive. A theoretical study of correlation between chemical structure versus biological activity of 1-nitro-2-phenylethane and prostaglandin-endoperoxide synthase was performed. In addition, an analysis of the conformational nitrophenylethane as well as changes in their chemical structure resulting in cinnamates and nitrostyrenes derivatives, for further evaluation of structureproperty. The conformational analysis was performed using the nitrophenylethane DFT/B3LYP the method with the basis set 6-31G (d) by varying the twist angle between the links of dihedro carbons C1-C2 linked to the phenyl and nitro groups, ranging from 5 ° intervals in the range of 0° to 180° in order to search for the lowest energy conformers. The conformer of the 180° dihedron O2N-C6H5-C1-C2 was significantly more stable and this can be explained in terms of the balance by the presence of seven geometries of lower energies. The HOMO and LUMO analysis shows that the phenyl and methylene groups contribute to the formation of this orbital. The calculation of energy and determination of electronic properties related to the mechanism of interaction with the cyclooxygenase showed a high correlation between nitro and carboxylic groups, which can be classified as bioisosters. The results of physico-chemical calculations show a greater correlation of the nitrophenylethane with acetylsalicylic acid, which may have related to its mechanism of action through interactions with Arg-120 and Ser-530. Calculated with the protonated guanidine by DFT/B3LYP/6-31G (d, p) for the complex containing the carboxylate group exhibit more favorable interaction energy with a value of -136.34 kcal / mol, compared with the molecule containing the nitro group with a value of -12.84 kcal / mol, which may explain the greater effectiveness of indomethacin, similar to biological outcomes. Nitrophenylethane derivatives showed a structural relationship with cinnamates derived from differing in the redox properties, which may favor the development of prototype structures and bioactive molecules from these molecular skeletons.Item Acesso aberto (Open Access) Estudo teórico do mecanismo redox de derivados quinolínicos na atividade antimalárica(Universidade Federal do Pará, 2010) SCALERCIO, Sarah Raphaella Rocha de Azevedo; BORGES, Rosivaldo dos Santos; http://lattes.cnpq.br/4783661132100859Malaria is a serious public health problem worldwide, causing socioeconomic deficits and contributing to subdevelopment in affected countries. In this context is important to study electronic properties, quinoline derivatives antioxidant potential and antimalarial activity relationship to design effective antimalariais prototypes. In this dissertation are used molecular modeling methods to study antioxidant and antimalarial structure-activity relationships selecting moieties and eletronic and conformacional parameters to improve farmacological activity and decrease derivatives toxicity. The HOMO and PI values analysis indicates that imino-tautomer is, probably, better antioxidant than amino-tautomer. It also observed that tautomers equilibrium is favored to amino-quinoline in the gas phase, and in water and chloroform using PCM method, with energy barriers values to 10.78 Kcal/mol, 21.65 Kcal/mol and 22.04 Kcal/mol, respectively. Then, may be noted that in quinoline analogues derivatives the electron-donor groups decrease the ionization potential, as exemple of the amino group at 8-position replaced by an alkylamine group. In 4- 8- amino-quinoline derivatives association observed that presence of quinoline moiety second nitrogen decrease its antioxidant activity, except in the 5-position, representing the most prominent group in the reduction of ionization potential and probably high antioxidant activity.Item Acesso aberto (Open Access) Planejamento de novos derivados da Edaravona(Universidade Federal do Pará, 2009-06-30) QUEIROZ, Auriekson Noronha; BORGES, Rosivaldo dos Santos; http://lattes.cnpq.br/4783661132100859A detailed theoretical study of the edaravone was carried out by DFT method using B3LYP/6-31G* basis set, with the objective to clarify the scavenging mechanism and influence of edaravone tautomerism under acid condition, which will be helpful to elucidate the radical-scavenging mechanisms in the ischemic process. Previous theoretical studies, tautomerization, solvent effects, and electron abstraction no were considered. In this work, the stability and reactivity were determined through geometric and energetic parameters were realized in gas phase and PCM methods in water and methanol. The acid or basic conditions were considered by bond dissociation or protonation energies may undergo anion or cation products, respectively. The antioxidant properties were calculated through HOMO, ionization potential (IP), and bond dissociation energies (BDE). HOMO and IP values showed that N-H tautomer is better antioxidant by electron abstraction, while BDE values showed that O-H tautomer is better antioxidant by hydrogen abstraction. The protonation is thermodynamically more favored than deprotonation. Furthermore, the protonation energy explain, theoretical, the reduced difference between N and O protonation. The protonation is thermodynamically more favored than deprotonation. The solvent effect decreased energies barriers to isomerization in O-H or N-H tautomers. In addition, three pyrazolone derivatives were evaluated its antioxidant activities comparated to edaravone, in an effort to develop the evaluated and pharmacophore antioxidant identification. The antioxidant activity of antypirine, dypirone, phenylbuthazone and edaravone was determined measuring the inhibition of two stables free radical DPPH and ABTS. Edaravone and phenylbuthazone exhibited more potent inhibition of DPPH and ABTS radical scavenging than dypirone, while antypirine not shown activity in all concentrations analyzed. Simultaneously, the DFT method can provide an antioxidant potential value to explain the structure-activity relationship (SAR). Furthermore, was evaluated their antioxidant activities and the ionization potential, HOMO, BDE X-H, and stabilization energies (DEiso) of the compounds have been calculated using the density functional theory (DFT) method at the B3LYP level, employing the 6-31G(d) basis set, to explore the SAR. All calculations have been performed by using the Gaussian 03 program, Hyperchem 7.5, and ChemOffice 2005. The results showed that derivatives with C-H in 4-position increased electron or hydrogen abstraction. Finality, the general strategy employed to design the target compounds was based on the studies of eighteen derivatives of edaravone. The SAR studies supported the three groups, such as more active, active and less active. Nine compounds were design with successful based in the structure of more active.Item Acesso aberto (Open Access) Síntese, capacidade antioxidante e estudo comparativo entre fenilhidrazonas e chalconas como derivados do paracetamol(Universidade Federal do Pará, 2014) BELEZA FILHO, Raimundo Ferreira Gouvea Pimentel; BORGES, Rosivaldo dos Santos; http://lattes.cnpq.br/4783661132100859The prostaglandin-endoperoxide synthase (PGES) and cytochrome P-450 are key enzymes in human, which are responsible for analgesic effect and toxicity of acetaminophen, respectively. Acetaminophen or paracetamol is a widely used over-the-counter analgesic and antipyretic drug and appears to be safe if used in normal therapeutic doses, but large doses of ACP produce hepatic and/or renal injury in humans and in experimental animals. At moment, the design of new acetaminophen derivatives has few impacts for its clinical applications of safe acetaminophen derivative. Thus, in this work a series of acetaminophen derivatives based on chalcone and hydrazone analogy was been investigated using quantum chemical calculations at the DFT/B3LYP theory level, with the 6-31G* basis sets. The HOMO, IP, BDEOH, and spin density contribution for the oxidation of an initial electron or hydrogen atom abstraction from the phenolic hydroxyl group was related with the quenching reactivity of tyrosyl radical to give N-acetyl-p-benzosemiquinone imine (NAPSQI). The second hydrogen abstraction was related with the chemistry reaction between amide group and hydroxyl radical to give N-acetyl-p-benzoquinone imine (NAPQI). The lowest BDEOH values were related with higher quenching values of the tyrosyl radical and the stability was related with the spin density for the initial electron or hydrogen abstractions. The highest BDENH values were related with small NAPQI formation and LUMO values with reactivity of NAPQI-like Michael system. Our results showed that some analogous may be a good strategy for safer drug design of analgesic compounds. The compounds were synthesized and their antioxidant property was estimated using theoretical methods. Some compounds can be good antioxidant. A proposed mechanism for the interaction between hydrazone derivatives and PGES was realized using molecular properties.