Dissertações em Química Medicinal e Modelagem Molecular (Mestrado) - PPGQMMM/ICS

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/14431

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Aspectos teóricos da interação entre compostos cefalosporínicos e a Proteína 5 de Ligação à Penicilina de Escherichia coli usando Dinâmica Molecular
(Universidade Federal do Pará, 2018-08-04) OLIVEIRA, Amanda Ruslana Santana; BARROS, Carlos Augusto Lima; http://lattes.cnpq.br/8902921733540173
Escherichia coli is an anaerobic Gram-negative bacillus that naturally inhabits the intestines of mammals. The diseases arise when the bacteria reaches other organs of our body, causing infections, mainly in the urinary tract of women, due to the proximity of the female urethra with the anus. Antibiotics were used in the treatment of these infections, such as antibiotics of the cephalosporin class, which are the group with the highest number of β-lactam antibiotics in clinical use. These compounds can inhibiting the enzymatic function of Penicillin-Binding Proteins (PBP), which is responsible for the final step of biosynthesis of peptidoglycan, an essential component for the survival of bacteria. In this work, the antimicrobial compounds cefoxitin, cefuroxime, cefotaxime, cephalothin, cefixime, cefmetazole and 7- aminocephalosporanic acid were chosen based on experimental studies of biological activity in the fight against the opportunistic Gram-negative pathogen Pseudomonas aeruginosa, to be studied theoretically through Molecular Dynamics simulations, binding free energy calculations, and interaction energy per residue, for the determination of their potential biological activity in inhibiting the enzymatic function of E. coli specific PBP, Penicillin Binding Protein 5 (PBP5), therefore its inhibition leads to cell death. More favorable binding free energies were obtained for the cefoxitin (crystallographic), cephalothin and cefuroxime ligands, -31.471 Kcal/mol, - 34.225 Kcal/mol and -35.085 Kcal/mol, respectively, and it was observed that the catalytic residues Ser44 and His216 presented more favorable energy contributions to the system formed by the cephalothin ligand. Thus, it was suggested that cephalothin has excellent potential for inhibition of the enzymatic function of E. coli PBP5, responsible for the final phase of transpeptidation of the peptidoglycan layer.
Acesso aberto (Open Access)
Atividade citoprotetora e cicatrizante da espécie Conocarpus erectus l em lesões gástricas induzidas em ratos Wistar adultos
(Universidade Federal do Pará, 2017-09-06) VIEIRA, Vaneza Rodrigues; MELLO, Vanessa Joia de; http://lattes.cnpq.br/9437589201689717
The pharmacological research has been aimed at the knowledge of regional folk medicine, in order to establish the scientific bases of their respective pharmaceutical products’ effectiveness. Among the many natural sources used in our region are the species Conocarpus erectus L, popularly known as the "mangrove bud", belonging to the Combretaceae family. Different parts of the plant such as leaves, stems, fruits and flowers have their biological activity studied, among them the anticancer and antimicrobial effects. Ethnopharmacological reports obtained in the region of Salinópolis - PA also described a potential use in digestive disorders. Although a great advance in the drug therapy used in the cases of gastric ulcerationhas been made, it is important to carry out studies that prove its validity. This work aims to verify the cytoprotective activity and cicatrizing activity of the lyophilisatebark teaobtained by decoction of the species Conocarpus erectus L (LCE) in acute and chronic gastric lesions. The methodologies for evaluating the cytoprotective effect were acute lesions inducted by indomethacin and ethanol, while the cicatrization effect was evaluated by chronic acetic acid-induced lesions in adult Wistar rats. The intragastric pH variation was measured by the pylorus ligament assay. The lyophilizate’santioxidant activity was evaluated by the DPPH assay, as well as the lipid perioxide levels’ that were evaluated by the TBA-RS method in chronic lesions induced by acetic acid 5 and 10%. The results showed cytoprotective activity of LCE by the indomethacin induction model reduced the ulceration index (IU) in the treated group by 51,49%, omeprazole group by 51,33% and sucralfate group by 71,28%, all of them when compared to the controlled group. On the model of ethanol LCE’s induction, the area affected was reduced by 90.94%, and in the sucralfate’s induction group, by 75.88% when compared with the controlled group. The LCE’s healing effect reduced gastric lesions to 5% in 80.11%, while the on omeprazole group to 52.75% and the sucralfate group reduced to 66.33%, whereas in the 10% gastric lesionsthe LCE group reduced 72.11%, the omeprazole 57.47%, and the sucralfate group 43.77% (p>0,05Anova, post testDunnett'sand Turkey). The LCE treatment showed an increase of 39% onintragastric pH when compared to control (p>0,05Anova, post testDunnett's e Turkey’s) and did not statistically showed any different from the omeprazole group by the model of pylorus ligation. The LCElyophilizate’santioxidant effect was confirmed by the DPPH assay, as it was diluted in 10x, 50x and 100x with a percentage of 67.65% ± 0.52, 73.22% ± 0.17 and 72.70% ± 1.39, respectively, when compared to the ascorbic acid antioxidant of 33,74% (AA) like this (p <0.05, Anovapost testDunnett). A lipid peroxidation evaluated in the lesions obtained by the 5%-acetic-acid-induction model showed that the average MDA levels in the nave group, controlled group and treated group LCE were 0.492 ± 0.0849, 1.579 ± 0.219, and 0.399 ± 0.092, respectively, showing that the LCE-treated group was able to reduce lipid peroxidation by 74.73% in comparison to the controlled group (p<0,05 Anovapost testDunnet) and it did not statisticallydiffer from the nave group. On the 10%-acetic-acid-model the average level of malonaldehyde in the nave group, controlled group and the LCE-treated group was 0.628 ± 0.042, 1.567 ± 0.234 and 0.441 ± 0.12, respectively. The LCE treated group managed to reduce by 71.85% the lipid peroxidation caused by acetic acid induced lesions when compared to the control group (p <0.05 Anovapost testDunnet).These results confirm the cytoprotective and cicatrizing effects of LCEand suggest possible action mechanisms associated with its antioxidant potential, as well as possible acid secretion inhibition.
Acesso aberto (Open Access)
Avaliação da atividade citotóxica e anti-invasiva da biflorina em linhagens de câncer gástrico do tipo intestinal
(Universidade Federal do Pará, 2019-12-03) MOTA, Elizangela Rodrigues da Silva; CALCAGNO, Danielle Queiroz; http://lattes.cnpq.br/1326603355062154; https://orcid.org/0000-0002-4429-2573
Natural products are sources of secondary metabolites with wide pharmacological applicability, including anticancer. Biflorin, a prenylated ortho-naphthoquinone that has been isolated from the roots of the Capraria biflora L. plant, has stood out as a potent prototype antitumor drug. However, despite promising potential, its antineoplastic capacity is incipiently applied to gastric cancer, one of the most incidente, aggressive and lethal cancers, nationally and globally. In this context, this study aimed to analyze the structure-toxicity relationship of biflorin by the redox in silico mechanism, as well as the in vitro cytotoxic and anti-invasive potential, using as a model strains of intestinal-type gastric adenocarcinoma metastatic (AGP01) and isolated from primary tumor (ACP03). In silico analysis showed that biflorin has a differentiated reactivity characteristic and can act as electron donor or acceptor in nucleophilic and electrophilic reactions, respectively. Moreover, when compared to other natural naphthoquinones such as β-lapachone and lapachol, it presented better redox properties and reactivity conditions, but with less toxic effect due to their ability to form more stable intermediates. The molecular simplification of biflorin also allowed to infer that the ortho-naphthoquinone functional group is probably the most related to naphthoquinones toxicity. Additionally, biflorin showed cytotoxic activity at considerably low concentrations for both strains, however, cytotoxicity was more pronounced for AGP01 (IC50 3.1 μM) compared to ACP03 (IC50 4.5 μM) at 48h treatment. Regarding antimetastatic activity, biflorin reduced the cell invasion capacity of the AGP01 strain only (p <0.0001). The results indicate that biflorin has cytotoxic activity for both gastric cancer strains AGP01 and ACP03, as well as anti-invasive specifically for metastatic cells AGP01. In addition, it was possible to clarify the probable selective cytotoxicity of biflorin based on its structural reactivity.
Acesso aberto (Open Access)
Avaliação do efeito do OTSSP167 em linhagens de adenocarcinoma gástrico com amplificação do gene MELK
(Universidade Federal do Pará, 2019-12-09) PINHEIRO, Thayanne Macedo; CALCAGNO, Danielle Queiroz; http://lattes.cnpq.br/1326603355062154; https://orcid.org/0000-0002-4429-2573
Gastric cancer is considered the fifth most common type of tumor in the world, and due to its heterogeneity, it is necessary to use individualized therapies that present less toxicity and greater efficacy during treatment. In a previous study, our group reported an increased copy number of the MELK gene in approximately 55.9% of tumors in patients with gastric adenocarcinoma and such tumor cell lines. This gene encodes maternal embryonic leucine zipper kinase (MELK) protein, a member of the serine/threonine kinase family, which participates in multiple cellular processes including cell cycle progression, cell proliferation, apoptosis, cell migration, and others. The increased expression has been observed in different cancers, including gastric cancer. Thus, the present study evaluated by in silico analysis the pharmacokinetic and pharmacodynamic properties of OTSSP167, its antineoplastic activity in gastric cancer cell lines ACP03 and AGP01, analyzing cell viability, the interference of this inhibitor in the protein expression of MELK in lineages, the ability of cell invasion and migration. In silico analyses, OTSSP167 showed a high probability of intestinal absorption, grade III toxicity and higher activity score for kinase inhibition. In vitro experiments, OTSSP167 showed cytotoxic activity in gastric strains, with higher cytotoxic activity against ACP03 (IC50 = 8.5nM). Also, this inhibitor was able to reduce MELK expression in ACP03 and AGP01 strains gradually according to the concentration of the compound. Regarding migration capacity, OTSSP167 was able to significantly inhibit the migration of ACP03 cells treated for 12 hours with three different concentrations of compound (4.25nM, 8.5nM, and 17nM), but in the 24-hour analyzes, there was only significance. OTSSP167 8.5nM and 17nM concentrations. However, the evaluation of cell invasion capacity after treatment with OTSSP167 for 48 hours did not yield significant statistical results. Thus, the results suggest that OTSSP167 has antineoplastic activity in lines with MELK gene amplification and inhibits cell migration capacity. Therefore, OTSSP167 has potential applicability in future therapies, requiring additional tests to delimit the mechanism of action of the compound.
Acesso aberto (Open Access)
Avaliação farmacológica da fração ácida do óleo de copaíba intercalada em hidróxidos duplos lamelares
(Universidade Federal do Pará, 2017-10-03) BARBOSA, Aline da Silva; QUEIROZ, Luana Melo Diogo de; http://lattes.cnpq.br/9775224837043003; https://orcid.org/ 0000-0001-5036-5639
Copaiba oil is traditionally used in the Amazon region of Brazil for pharmacological purposes as pain and inflammation. The acidic fraction of copaiba oil (FAOC) consists of diterpenes and, among them, excels copalic acid as major component, being endowed with anti inflammatory activity in vitro. In addition to the research for new active principles, there is also interest in management models that optimize the action of drugs. For this, an alternative is the controlled release of drugs, which can be obtained by the intercalation of these in Lamellar Double Hydroxides (HDLs). Thus, this study aimed to evaluate the antinociceptive and anti-inflammatory activity of the FAOC and FAOC intercalates in HDL (FAOC-HDL) in vivo models of nociception and inflammation. Male (Mus musculus) mice (4 to 6 weeks old, weight 25-35g) were divided into groups (n = 6) and treated orally (0.1mL/10g), with negative control (vehicle), HDL, FAOC, FAOC-HDL, and positive control, 1h, 24h and 48h before each test. First, was determined the median effective dose (DE50) and then the experimental models of acetic acid-induced abdominal contraction, formalin test, croton oil induced ear edema, carrageenan-induced paw edema test and peritonitis induced by carrageenan. The ED 50 found was FAOC (98 mg/kg) and FAOC-HDL (222.9 mg/kg). After 1 h of treatment, FAOC (98 mg/kg) and FAOC-HDL (222.9 mg/kg) significantly inhibited the number of abdominal writhing respectively in 49.99% (22,67± 1,56) and 56,99% (19,5 ± 2,69), the paw licking time in the formalin test was 28.93% (113.6 ± 12.45) and 60.79% (62.67 ± 11, 02) in the second phase of the test, development of ear edema in 25.59% (2.53 ± 0.21) and 47.65% (1.78 ± 0.20) and development of paw edema in the 2nd and 3rd hour of the test and the migration of total leukocytes by 73.17% (1.95 ± 0.38) and 75.69% (1.77 ± 0.28) and neutrophils in 62.82 (1.61 ± 0.31), 91.0% (0.39 ± 0.10) in the peritonitis. There was also a significant effect on treatment with FAOC-HDL (222.9 mg/kg) after 24 h of treatment, inhibiting the number of abdominal writhes in 58.34% (20.0 ± 3.97), lambda time of the paw in the formalin test 33.97% (98.83 ± 13.64), the development of ear edema in 57.05% (2.47 ± 0.36) and the development of paw edema in the 3rd hour of the test in 30.28%, (0.27 ± 0.02). Thus, the results obtained show antinociceptive and anti-inflammatory effect of the FAOC and, underpinning this effect by the controlled release of FAOC intercalates in HDL.
Acesso aberto (Open Access)
Curso temporal da degradação e restauração de redes perineuronais após a ação da enzima chabc entregue via implante de biomembrana no córtex cerebral de ratos
(Universidade Federal do Pará, 2020-03-18) REIS, Rafaela Martins; BAHIA, Carlomagno Pacheco; http://lattes.cnpq.br/0910507988777644; https://orcid.org/0000-0003-3794-4710
The chondroitin sulfate proteoglycans (CSPGs) founded on the extracellular matrix (ECM) of nervous tissue are the main components related to the restriction of neuroplasticity. When condenserd, they form the perineuronal nets (PNNs) and their appearance coincides with the end of the critical period of plasticity and reduction of the reorganization potencial of the central nervous system (CNS). The degradation of PNNs by the enzyme chondroitinase ABC has been used as a tool for reopening periods of neuroplasticity in adult nervous system.. In this work, we analyzed the temporal dynamics of PNNs degradation and restoration in the primary somesthetic cortex (S1) after degradation by the enzyme ChABC in an in vivo experimental model using a biomembrane vehicle for focal delivery and without damaging nervous tissue. In this way, we used adult Wistar rats that were submitted to the implantation of the biomembrane made with ethylene-vinyl-acetate saturated with the enzyme ChABC, with 1, 3 and 7 days of survival time after implantation, using the non implanted side cerebral hemisphere as a control. Our results demonstrated that degradation via implantation of the biomembrane saturated with ChABC was efficient from day 1, with a drastic reduction in the implanted hemisphere (LH) of mature PNNs. There was also a significant increase in the number of immature PNNs in the HD even 7 days after implantation. Neither the biomembrane or the enzyme triggered signs of a neuroinflammatory process or glial activation, but the removal of ECM components interfered with the immunostaining of nerve cells 7 days after the implantation of the biomembrane with ChABC. Therefore, we concluded that the ethylene-vinyl-acetate polymer biomembrane was efficient for focal delivery of the ChABC enzyme and promoted degradation of PNNs in the S1 area of adult rats, did not cause mechanical damage to the nervous tissue, nor activated glial reactivity and the area of enzymatic degradation decreases over time (from 1 to 7 days).
Acesso aberto (Open Access)
Estabelecimento e caracterização citogenética de linhagem celular de carcinoma adenoide cístico
(Universidade Federal do Pará, 2019-12-16) SILVA, Fernanda Jardim da; CALCAGNO, Danielle Queiroz; http://lattes.cnpq.br/1326603355062154; https://orcid.org/0000-0002-4429-2573
Adenoid cystic carcinoma (ACC) is a rare neoplasm that mainly affects the head and neck regions, especially salivary glands. Growth is slow, but with but with a propensity to perineural invasion, local postoperative recurrence and metastasis. The most used treatment for this type of tumor is surgery followed by postoperative radiotherapy. The molecular characteristics of ACC are unclear, and unfortunately, the rarity of this type tumor limits to obtain in vitro and in vivo models that contribute in the investigation of pathogenesis and more efficient treatments. In the present study, a cell line was established and characterized for the evaluation of anticancer molecules. For this, it was obtained tissue samples of ACC off the tubular histological subtype from the retromolar trigone and a blood sample from a 59-year-old female patient. Array Comparative Genomic Hybridization (aCGH) performed molecular cytogenetic characterization in tumor tissue and cell line, while blood was genotyped for ancestry. Cell culture established from the collected tumor tissue showed rapid growth of tumor colonies from passage 18, stabilizing at passage 30. Blood genotyping revealed an ancestral contribution of 19% Amerindians, 31.5% Europeans and 49.5% of blacks. In cytogenetic analysis, gains were observed in loci harboring important genes such as EGFR (7p22.1-p11.2), BRAF (7q32.3-q34), HER2 (17q12-q21.2) and SMARCA1 (xq25-q27.1). Also in the lineage, loss (6q23.3-q25.1, PLAGL1 gene locus) and deletion (9p21.3-p21.1, CDKN2A/B gene locus) were observed; In tissue, only gains were observed (9q34.3, NOTCH1 locus and 5q32, PDGFRβ locus). The loss in 19p13.3-p12, locus of the CDKN2D gene, stands out as a common event in both samples. These findings corroborate other studies in the literature and make the established lineage a good in vitro model that can assist in the investigation of the pathogenesis of CAC and the basic research for new therapeutic modalities.
Acesso aberto (Open Access)
Estudo do mecanismo conformacional da proteína 3-hidroxi-3- metilglutaril Coenzima A Redutase (HMGR) com as estatinas e substrato através de Dinâmica Molecular, PCA e Energia Livre
(Universidade Federal do Pará, 2017-08-03) COSTA, Clauber Henrique Souza da; SILVA, Jerônimo Lameira; http://lattes.cnpq.br/7711489635465954; https://orcid.org/0000-0001-7270-1517
Cholesterol is a substance of paramount importance for all animals. However, its high level in the human body is linked to the two major diseases that kill the world: ischemic heart disease and stroke. One of the synthetic drugs used in the treatment of hypercholesterolemia are statins, inhibitors of 3-hydroxy-3-methylglutaryl Cozyme A reductase (HMGR), which act primarily on the liver by inhibiting a conversion of the HMG-CoA substrate into mevalonic acid, which is the metabolite Cholesterol precursor. Studies Molecular Dynamics (MD) combined with Principal Component Analysis (PCA) were performed to verify the mechanism of the changes in the Cterminal Flap domain form (residues His861, Leu862, Val863, Lys864, Ser865 and Hys866) after binding substrate and efficient statins in inhibiting the HMGR enzyme. A total of 500 ns of MD simulation time were performed in this study. Binding Free Energies calculations were used, which estimate that the structural mechanism of the Flap is related to an action of the HMGR protein, since domain control or access to the active site of the enzyme. The results also show that the structural modification of Flap increases the energy contribution of the system by involving larger interactions with catalytic residues and, consequently, an ability to inhibit cholesterol production, as observed for the catalytic His866, which has a very favorable contribution when the Flap is in the closed state, with energy of -14,802 Kcal/mol, and when the Flap passes to the open state the contribution is less favorable, with -1,022 Kcal/mol, for 1 inhibitor, showing that in the closed state the catalytic residue is directly involved and contributes in a favorable way to the system, leading to a better understanding of the conformational changes of HMGR after a binding of statin derivatives and HMG-CoA substrate.
Acesso aberto (Open Access)
Modelo experimental para indução de hemiparkinsonismo por 6-hidroxidopamina em primatas sapajus apella e avaliação das alterações motoras
(Universidade Federal do Pará, 2019-06-09) LEAL, Leon Claudio Pinheiro; KREJČOVÁ, Lane Viana; http://lattes.cnpq.br/2604693973864638; https://orcid.org/0000-0001-8016-5283; BAHIA, Carlomagno Pacheco; http://lattes.cnpq.br/0910507988777644; https://orcid.org/0000-0003-3794-4710
Parkinson's disease is currently the second most common neurodegenerative disease in the world, with a high incidence in North and South America and Europe, for more than 50 years we have not seen any revolutionary treatment for the disease and many aspects of its neuropathology that still remain without a concrete enlightenment, in this feeling the experimental model in primates approaches the human reality are invaluable value for the development of new therapies and elucidation on mechanisms related to the disease. The 6-hydroxydopamine model in primates is a model that mimics some motor symptoms characteristic of PD. The present study aimed to develop a protocol for the induction of HemiParkinsonism in Sapajus apella primates. Three Sapajus Apella monkeys, all adult males, were submitted to daily conditioning sessions using the positive reinforcement clicker technique for primate chair positioning. Concurrently, the staircase and Brinkman tray motor tests were performed to determine laterality by the manual preference and dominance attributes. After this period, two 6-OHDA induction protocols were performed, the first protocol was injected into 10 sites in the nucleus striatum and the second protocol was injected into 10 sites in the nigrostriatal pathways, one week after the injections were performed twelve weeks of clinical analysis . All animals learned the input and positioning behaviors in the chair in a minimum of 30 sessions using pure positive reinforcement. The results of the staircase test demonstrated that the animals presented laterality consistent with the assignments of manual preference and dominance. The Brinkman test, specifically, presented lower sensitivity for determination of the same attributes, despite being the most commonly used test. Clinical analysis revealed that the second induction protocol had more motor symptoms characteristic of PD. Induction by 6-OHDA in the nigrostriatal pathways has been shown to be a good induction method for treatment studies and for a better understanding of the disease.
Acesso aberto (Open Access)
Planejamento e desenvolvimento de análogos da nitazoxanida
(Universidade Federal do Pará, 2018-09-25) FERREIRA, Lanalice Rodrigues; BORGES, Rosivaldo dos Santos; http://lattes.cnpq.br/4783661132100859; https://orcid.org/0000-0003-4072-7573
Nitazoxanide is a molecule applied in the antihelminthic therapy and has a broad spectrum as antiparasitic agent. In biological studies by using this molecule, new therapeutic targets and good results were found. Nevertheless, it still has some chemical and pharmaceuticals problems which need improvements. The objective of the study is the design and development of stable nitazoxanide derivatives using molecular modeling and organic synthesis approaches. All calculations of electronic properties such as frontier orbital (HOMO and LUMO), ionization potential (IP) and electronic affinity (AE), electrostatic potential map (MPE) were performed using the Gaussview e Gaussian. The theoretical study of nine amino-nitro-azolic derivatives, an essential moiety of nitazoxanide pharmacophore, was performed using the DFT/B3LYP/6-31G (d,p) method and showed that thiophene ring modifications can reduce the redox potential changing the reactivity and toxicity. All derivatives have better electrophilic properties and depends on the presence of nitro group. These results are confirmed by maps of electrostatic potentials and can indicated the most reactive regions that probable act on electrophilic attacks. Physicochemical parameters of nitazoxanide analogues were also evaluated using the DFT/B3LYP/6-31+G (d,p) method. A significant increase in the electron donating capacity for these new molecules from the HOMO, LUMO and GAP values was observed. An additional nitro group on ring structure beget compounds that have great stability and electron-accepting capacity. This electronic property is essential for biological activity on nitro compounds. The electrostatic potentials for nitazoxanide and its related analogues show the significant negative charge density on the nitro region. In addition, a conformational analysis of nitazoxanide, tizoxanide and a nitazoxamide derivatives was performed. The lower conformer of nitazoxanide agrees with the crystallographic structure. The more stable structures of the derivatives are related to their conformational similarity. The nitazoxanide molecule and three other derivatives have been synthesized and are available for biological evaluation on future works.
Acesso aberto (Open Access)
Planejamento e desenvolvimento de derivados do muscimol com propriedades antioxidantes
(Universidade Federal do Pará, 2019-12-09) SOUSA, Alanna Crystine Lima Farias de; BORGES, Rosivaldo dos Santos; http://lattes.cnpq.br/4783661132100859; https://orcid.org/0000-0003-4072-7573
Muscimole is a psychoactive izoxazole compound extracted from mushrooms of the genus Amanita muscaria has been studied as a GABA inhibitor due to behavioral genes, since its structural structure is based on mammalian neurotransmitters GABA and glutamic acid. Due to its high selectivity and its own potential for neural activity, it is able to act as a drug, since it has a higher affinity for the GABAA receptor than GABA. Since the 1980s studies suggesting that GABA and muscimol are related to serotonin concentration, where increased GABA concentration or muscimol injection increases serotonin concentration and decreases inactive product after serotonin. oxidation, 5-HIAA. For this reason, this work aimed to plan and develop muscimol derivatives as an alternative for increase the serotonin using antioxidant activity. For this reason, this work aimed to plan and develop muscimole derivatives as an alternative for the treatment of anxiety and depression. For this, was used the drug planning method known as bioisosterism, which is characterized by being compounds or subunits of bioactive substances with similar structural characteristics, as well as similar physical and chemical properties with the ability to present analogous biological properties, can be agonists or antagonists. Firstly, a study was made of the groups that are responsible for the biological activity through the muscimole pharmacophores, where the groups that interact with the GABAA receptor are the -NH2 groupings, the isoxazole ring, as well as the oxygen present in the carbonyl. Then molecular modeling was performed, which was performed using the DFT B3LYP 6-311G (2d, 2p) method to verify the values of HOMO, LUMO, GAP, ionization potential (IP), bond energy dissociation, hydrogen atom transfer and single electron transfer, where it was found that the derivative S1 presented values equal -7.61 eV, -1.36 eV, -6.25 eV, 205.87.85 kcal/mol, 80.81 kcal/mol, -15.45 kcal/mol e -6.99 kcal/mol, respectively. The derivative S2 presented values of -6.80 eV, -1.08 eV, 5.72 eV, 198.41 kcal/mol, 77.73 kcal/mol, -18.53 kcal/mol e -0.47 kcal/mol, respectively. When compared with GABA, it was found that they are reactive, among which derivative S2 is more reactive, presenting lower GAP value compared to S1, and with PI values, it was found that derivative S1 has a lower electron donor capacity than derivative S2, highlighting that the best route is through the hydrogen donation mechanism. Then, the regioisomers derivatives were synthesized with a yield for S1 and S2 of 74,08% and 60,42%, respectively, as well as characterization through the melting point, where the derivative S1 had equal melting point. at 114,5 ° C - 115 ° C and S2, 182,5 ° C, showing that the synthesized molecules are pure, since they were compared with the data in the literature. With these data it is possible to say that muscimol derivatives have high antioxidant activity.
Acesso aberto (Open Access)
Planejamento e síntese de novos derivados relacionados ao piroxicam
(Universidade Federal do Pará, 2019-12-09) OTA, Sirlene Sayuri Barros; BORGES, Rosivaldo dos Santos; http://lattes.cnpq.br/4783661132100859; https://orcid.org/0000-0003-4072-7573
Piroxicam is a drug belonging to the group of oxicams, derived from phenolic acids, in the class of NSAIDs. Although not the drug of choice in some treatments, the drug is indicated for the treatment of acute musculoskeletal disorders, post-traumatic and postoperative pain, rheumatoid arthritis and osteoarthritis, primary dysmenorrhea, endometriosis and hemorrhagic cyst. Like non-steroidal anti-inflammatory drugs, piroxicam is able to inhibit prostaglandin synthesis from arachidonic acid by competitively reversible inhibition of COX activity, with some predominance to inhibit COX-2 activity. Photosensitivity is one of the adverse effects caused by the drug, being observed in about 1% of patients. In addition, various techniques have been used to improve the stability of piroxicam without diminishing its potential. Thus, the objective of this paper is to plan, synthesize and evaluate more stable derivatives related to the phototoxicity of the study drug. Calculations of electronic properties such as high energy occupied molecular orbital (HOMO), low energy occupied molecular orbital (LUMO) and ionization potential (IP), as well as reactivity index calculations (Mulliken, CHELPG and Fukui) were calculated. performed using the Gaussview and Gaussian 2009 packages. The proposed derivatives have been synthesized through classical reactions such as esterification and nucleophilic substitution and are in the process of purification. The results of the HOMO and LUMO values showed that the D4 molecule has a better electronic distribution, with the second lowest HOMO value and the highest LUMO value, and can be considered the most stable. The D6 molecule proved to be the most reactive derivative and this can be explained by the presence of two hydroxyls in the naphthalene ring of the derivative, influencing the reactivity of the molecule. Based on the GAP values, the nitrated derivative (D2) presented lower value (3.36 eV), indicating high reactivity. The D4 molecule presented the highest GAP value, confirming its stability. In the analysis of Mulliken, CHELPG and Fukui loads of piroxicam, differences in substitution orientation were observed, probably due to the difference in calculations performed for each index. In the theoretical results of the chemical reactivity study using UV-Vis, piroxicam and its naphthalenic derivative showed completely different profiles, referring to its three main peaks, being the most expressive in the C = C system, indicating that in the benzothiazine system it functions as a reactive alkene after energy absorption.Thus, the molecular modification by the naphthalene system presented a compound with higher chemical stability and lower reactivity.
Acesso aberto (Open Access)
Planejamento, síntese e aplicações de derivados naftosalicílicos como antioxidantes
(Universidade Federal do Pará, 2017-08-30) BARROS, Valéria Araújo; BORGES, Rosivaldo dos Santos; http://lattes.cnpq.br/4783661132100859; https://orcid.org/ 0000-0003-4072-7573
Salicylate derivatives are successfully applied as analgesics, antipyretics, anti-inflammatories and in cancer prevention, especially rectal colon. They reduce the risks of many diseases associated with elderly. However, adverse effects related to gastrointestinal events are always associated to its main constituent acetylsalicylic acid. These aspects are linked to their chemical stability and affinity for some biological receptors. The aims of this work are the design, synthesis and applications of naphthalene-salicylic derivatives as antioxidants. Thus, a theoretical study of the studied compounds was carried out. Calculations of electronic properties such as frontier orbitals HOMO-LUMO, ionization potential (IP), bond dissociation energy of phenolic moiety (BDEOH), and spin density contributions were performed by using density functional theory (DFT) at the B3LYP/6-31G (d, p) level of theory on Gaussview and Gaussian computational packages. Some of these compounds were synthesized by using classical methods. The theoretical results showed that both additional hydroxyl or substitution on benzene ring for naphthalene increase the antioxidant capacity in the same values with small dissimilarities among acid, ester, and amide derivatives. A synergistic effect was observed when both are used together, producing the most potent molecules. In addition, spin density calculations indicated a regioselective pathway can be gotten from monohydroxylic derivatives, with high possibility of in vivo generating of dihydroxy derivatives mainly at the para position relative to the phenolic group, through enzymatic or non-enzymatic reactions. Finally, the replacement of the naphthalene ring instead of the benzene ring increases both reactivity and chemical stability for the quinone-type intermediates, explaining how these compounds will play a role in the preventive mechanisms and way treatment of cancer. Anti cancer and anti-inflammatory activities are being performed for some of the synthesized compounds.
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Síntese, intercalação, caracterização estrutural e análise biológica de nanopartícula carreadora de ácido kójico
(Universidade Federal do Pará, 2017-11-30) DIAS, Amarílis Aragão; SILVA, Jerônimo Lameira; http://lattes.cnpq.br/7711489635465954; https://orcid.org/ 0000-0001-7270-1517; ALVES, Claudio Nahum; http://lattes.cnpq.br/8315600067791313; https://orcid.org/ 0000-0001-6576-4229
Intercalation of species with pharmacological activity in layered double hydroxides (LDHs) is a growing field in academic and industrial research, these compounds are capable of promoting the controlled release of drugs. In this work we merge the kojic acid in LDH nanoparticles of Mg2+/Al3+ by co-precipitation method. This substance has many applications in various fields of research, however it is easily susceptibile to photo-oxidation which causes organoleptic and chemical modifications of its structure. Recently kojic acid was introduced as a potent inhibitor of Leishmania cultures, we believe that the particular properties of HDL, such as photoprotection, and stabilization of the interleaved facilitate the production of a material resistant to possible applications for health. All samples were prepared by the co-precipitation method, were further characterized by X-ray diffraction, Raman, IR, UV-vis spectroscopy, thermogravimetry, and biological evaluations of Leishmania cultures. Our results demonstrate that HDL has 53.018% AK intercalated kojic acid and is able to withstand high temperatures, in addition to having an anti-leishmania potential.

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