Navegando por Orientadores "SANTOS, Lourivaldo da Silva"

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Acesso aberto (Open Access)
Acetilbergenina: obtenção e avaliação das atividades antinociceptiva e anti-inflamatória
(Universidade Federal do Pará, 2010-01-22) BORGES, Jaqueline Cibene Moreira; SOUSA, Pergentino José da Cunha; http://lattes.cnpq.br/9909053957915090; SANTOS, Lourivaldo da Silva; http://lattes.cnpq.br/3232898465948962
Endopleura uchi (Huber) Cuatrec. (Humiriaceae), a Brazilian Amazon plant, commonly known as “uxi”, is used in folk medicine for the treatment of several pathologies, such as arthritis. Bergenin, one of the chemical constituents of E. uchi, has several biological activities, including anti-inflammatory and antinociceptive activities. In order to obtain a more potent derivative than bergenin it has decided to acetyl this substance. Acetylbergenin was tested in nociception and inflammation models. Bergenin was isolated from the chromatographic fractionation of aqueous extract from stem bark of E. uchi and the acetylbergenin was obtained by acetylation of bergenin. The substances were identified based on spectral analysis of 1H NMR, 13C NMR, DEPT and COSY, and comparison with literature data. For nociception models were carried out the abdominal writhing test, hot plate test and formalin test, while in the inflammation models were carried out the croton oil-induced ear edema, rat paw edema induced by carrageenan and dextran, carragenin-induced peritonitis test. Furthermore, the model of gastric ulcer induced by stress was used to assess the potential ulcerogenic of the substance. In the abdominal writhing test induced by acetic acid 0.6%, acetilbergenin doses of 1, 5, 10, 15 and 25 mg / kg blocked the number of writhing in 28.2%, 52.7%, 61.1 %, 68.3% and 95.0%, respectively, and dose-dependent manner when compared to the control group. The calculated ED50 was 6.8mg/kg. In the hot plate test (55ºC), acetylbergenin (6.8 mg/kg) did not induce alterations in the latency time when compared to the control group. In the formalin test, acetylbergenin (6.8mg/kg) inhibited 88.30% the algic stimulus in the second phase (inflammatory) compared to the control group. Furthermore, naloxone reversed the effect of acetylbergenin the second phase of this test. In the croton oilinduced dermatitis, acetylbergenin (6.8 mg/kg) provoked inhibitory effect in 75.60% in comparison to the control group. In the paw edema induced by carrageenan, acetylbergenin (6.8 mg/kg) was able to reduce the development of edema from the 2nd to the 5th hours compared to the control group. In the paw edema induced by dextran, acetylbergenin (6.8 mg/kg) reduced edema at all times. In carragenininduced peritonitis, acetylbergenin (6.8mg/kg) blocked 70% of the neutrophils number compared to the control group. In the trial of gastric ulcer, acetylbergenin blocked 78.55% in the generation of gastric lesions by stress when compared to indomethacin. The results suggest that acetylbergenin has an antinociceptive and anti-inflammatory activity which, according to the tests employed, is probably of peripheral origin.
Acesso aberto (Open Access)
Atividades antimicrobiana e antipromastigota de extratos e frações de Virola surinamensis (Rol ex Rottb.) Warb (Myristicaceae)
(Universidade Federal do Pará, 2012-09-13) SARAIVA, Maria Elinete Veras; DOLABELA, Maria Fâni; http://lattes.cnpq.br/0458080121943649; SANTOS, Lourivaldo da Silva; http://lattes.cnpq.br/3232898465948962
The present study aimed to evaluate the antimicrobial activity of extracts and antipromastigota V. surinamensis and its fractions. To obtain the extracts have been used increasingly polar solvents (hexane, ethyl acetate and methanol) and the ethyl acetate extract was fractionated into open column chromatography, using as stationary phase silica gel and eluents such as mixtures of hexane and ethyl acetate gradient increasing polarity. To evaluate the antimicrobial activity was used in agar diffusion test being used the following microorganisms: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. The active fraction was subjected to microdilution, which determined the minimum inhibitory concentration (MIC). In assessing the activity antipromastigota used the Leishmania amazonensis and L. chagasi, being determined the minimum inhibitory concentrations and 50% inhibitory concentration (IC50). Extracts hexane, ethyl acetate and methanol were subjected to agar diffusion test, and there were no inhibitions of bacterial and fungal growth. Just FA3 ethyl acetate fraction obtained from the ethyl acetate extract inhibited the growth of S. aureus in the agar diffusion test. But in this fraction microdilution proved inactive (MIC> 1000μg / mL). Only the hexane extract was active in promastigote forms of L. amazonensis and L.chagasi. In short, only the hexane extract was active in promastigote forms of Leishmania.
Acesso aberto (Open Access)
Estudo químico e atividade biológica de Nephrolepis brownii e da biomassa produzida pelo fungo endofítico NB-1 associado à espécie
(Universidade Federal do Pará, 2016-09-23) CAVALCANTE, Francisco Otávio da Rocha; GUILHON, Giselle Maria Skelding Pinheiro; http://lattes.cnpq.br/6603694331802001; SANTOS, Lourivaldo da Silva; http://lattes.cnpq.br/3232898465948962
The species Nephrolepis brownii, commonly known as fern, can be easily found in the Amazon region. It is a creeping species, which spreads easily and inhibits small around plants. N. brownii like other ferns are also known as "sky ladder", which are widely used as ornamental plants and medicinal purposes. This is the first work which is carried out the chemical study of N. brownii, where the Fernene substances were isolated (S1) and Pinitol (S2) from the aerial parts of it. In the study of the essential oil of N. brownii were identified 80 substances, most belonging to the aldehyde functions (26.62%), alcohol (25.11%) and ketone (17.15%), among those Z-2-(3,3-dimetilciclohexlidene)-ethanol (8.65%), safrole (8.81%) undecan-2-one (8.89%), teaspirano (8.99%), n-tridecane (9.05 %), n-undecanal (9.20%), o-methyl-orcinol (9.32%) and deca-(2E,4E)-dienal (9.41%) were majority. Aerial parts of N. brownii was isolated as endophytic fungus called NB-1, which was grown on solid medium (rice) and liquid medium (Czapek) for the growth of fungal colonies and obtain extracts. From the ethyl acetate extract fungal (rice) were isolated p-Hydroxybenzaldehyde substances (S3), p-hydroxyphenylacetic acid (S4) and 4-hydroxybenzoic acid (S5). From the culture in liquid medium (cazpek) were isolated substances ergosterol peroxide (S6) stoloniferol B (S7) both phases ethyl acetate (1 and 2). The NB-1 fungus has been shown to biotransform substances such as chalcone 3-(2,3,4-trimethoxyphenyl)-1-(4-methoxy)-2-propen-1-one and aromatic ketone 4-nitroacetophenone. Tests were conducted to evaluate the phytotoxicity of extracts and compounds in the face of evil seeds and kills pasture where the best results were for EBM/Hex, EBM/EtOAc and EBM/n-But extracts, highlighting the EBM / AcOEt had 100% inhibition against the germination of seeds of malice. The EFMeOH extract showed significant inhibitory effect on the germination of seeds of malice and kill pasture, with high values, 75% and 100%, respectively. The substances tested showed no satisfactory results in the face of evil seeds and kills pasture. It investigated the biological potential of the substances S1, S2, S3 and S5, which have not been active for L. amazonensis promastigote form a species.
Acesso aberto (Open Access)
Planejamento e avaliação in sílica de análogos de lapachol em enzima alvo de Leishmania (Leishmania) amazonensis
(Universidade Federal do Pará, 2017-11-09) FERREIRA, Érica Patrícia dos Reis; DOLABELA, Maria Fani; http://lattes.cnpq.br/0458080121943649; SANTOS, Lourivaldo da Silva; http://lattes.cnpq.br/3232898465948962
The study aims to design and evaluate antiamastigote activity of Leishmania amazonensis and cytotoxicity Lapachol analogues. The studies predictive pharmacokinetic characteristics were performed, toxicological, biological activity and molecular docking or molecular docking. For pharmacokinetic and toxicological characteristics used the online program PreADMET while biological activities were assessed by online program Prediction Spectra of Activity is Substances (PASS). For the molecular docking analysis, the therapeutic target was selected Triponationa reductase, and the evaluation of interaction between the molecules and target this protein was performed by the virtual Molegro program docker (MVD). The extraction and isolation of Lapachol was performed and its identification was performed by nuclear magnetic resonance spectroscopy (NMR). All analogs Lapachol and are well absorbed from the intestine with the absorption ranging from 79.745% to 99.056%, furthermore inhibit the cytochrome P450 (CYP). Almost half of the molecules tested (42.1%) had moderate distribution into the central nervous system (CNS), including Lapachol, while the remainder have high distribution. The results of the toxicity of the molecules studied suggest that 63.16% are mutagenic and carcinogenic, which includes Lapachol and 10.5% and 5.26% are carcinogenic and mutagenic, respectively, but showed 21.05% not exhibit cytotoxicity. In molecular docking the substances studied showed less energy than the standard substance, although they have good interaction with energies between 94.343 to 115.635 kJ / mol. The Lapachol was isolated and identified. According with to the analogo results show that with the best characteristics was the 3,4-dihydroxy-2- (2-hydroxy-3-methylbutil) nafthalen-1 (4H) -one.