Browsing by Author "Oliveira, Djalma Menezes de"

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    Biological activities of extracts from Padina Boergesenii and Sargassum Stenophyllum, seaweeds naturally found in Baia de Todos os Santos, Brazil.
    (2015) Oliveira, Naiara Maia; Meira, Carla Larissa Costa; Aguiar, Rosane Moura; Oliveira, Djalma Menezes de; Moura, Carlos Wallace do Nascimento; Vieira Filho, Sidney Augusto
    Objective: Here we present the results of the biological potential as antioxidant, anti-cancer and leishmaniscidal from extracts of Padina boergesenii Allender & Kraft and of Sargassum stenophyllum Martius, seaweed species commonly found in bay of the Brazilian Atlantic coast named Baía de Todos os Santos, state Bahia. In addition, we reported on the chemical composition of extractive fractions from these algae. Methods: Phytochemicals prospecting methods such as thin layer chromatography (TLC) and spectrometry in the UV/Vis region were used to identify the chemical class of constituents from these algae extracts. Antioxidant potential of the fractions was evaluated using the α,α-diphenyl-β-picrylhydrazyl (DPPH) free radical scavenging method. The cytotoxic potential of seaweed extracts against the human breast cancer (MFC-7) cell lines was evaluated using the sulforhodamine B (SRB) colorimetric assay. The leishmanicidal effect of algae extracts against promastigotes of Leishmania amazonenses Laison & Shaw 1972 was evaluated using amphotericin B (AMB) as positive control. Results: Were detected flavonoids, steroids, carotenoids, anthocyanins and phenolic compounds from algae extracts in hexane, chloroform and n-butanol. Overall, extractive fractions showed moderate antioxidant activities in comparison with quecertin, butylated hydroxytoluene and gallic acid. Fractions from P. boergesenii and chloroform fraction of S. stenophyllum presented significant activity against MCF-7 cells by inhibiting the cells grown among 55.0 to 66.0 %. These results were closely similar to inhibition reached by colchicine (67.0 %) used as positive control. No antileishmanial significant effect was observed for P. boergesenii and S. stenophyllum extracts at the tested conditions. Conclusion: The results indicated a promissory pharmacologic potential for the P. boergesenii and S. stenophyllum extracts, Which open perspectives to the isolation of their active constituents.
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    Chemodiversity of essential oils from nine species of Celastraceae.
    (2020) Duarte, Lucienir Pains; Camargo, Karen Caroline; Vidal, Diogo Montes; Pereira, Hebert Vinicius; Pereira, Rafael César Gonçalves; Aguilar, Mariana Guerra de; Sousa, Grasiely Faria de; Vieira Filho, Sidney Augusto; Simões, Maria O. Mercadante; Messias, Maria Cristina Teixeira Braga; Oliveira, Djalma Menezes de
    Extracts and compounds obtained from several species of Celastraceae family are reported as potential sources of drugs due to their diverse pharmacological properties. Nevertheless, essential oil composition from these species is still little known. This work aimed the analysis of essential oils obtained from different Brazilian Celastraceae species. A total of seventeen oils were obtained using hydrodistillation process and analyzed by gas chromatography/mass spectrometry (GC/MS). Principal component analysis (PCA) allowed the identification of a chemical composition pattern among the analyzed essential oils. Some compounds were more frequent among Celastraceae species, such as cis and trans-oxide linalool (14/17 oil samples), nerylacetone (13/17), linalool (11/17), β-ionone (10/17), α-ionone (9/17), nerolidol (10/17), decanal (10/17) and dodecanoic acid (10/17). These results contribute to the chemophenetics of Celastraceae species.
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    Combined experimental powder x-ray diffraction and DFT data to obtain the lowest energy molecular conformation of friedelin.
    (2012) Oliveira, Djalma Menezes de; Mussel, Wagner da Nova; Duarte, Lucienir Pains; Silva, Grácia Divina de Fátima; Duarte, Hélio Anderson; Gomes, Elionai Cassiana de Lima; Guimarães, Luciana; Vieira Filho, Sidney Augusto
    Friedelin molecular conformers were obtained by Density Functional Theory (DFT) and by ab initio structure determination from powder X-ray diffraction. Their conformers with the five rings in chair-chair-chair-boat-boat, and with all rings in chair, are energy degenerated in gas-phase according to DFT results. The powder diffraction data reveals that rings A, B and C of friedelin are in chair, and rings D and E in boat-boat, conformation. The high correlation values among powder diffraction data, DFT and reported single-crystal data indicate that the use of conventional X-ray diffractometer can be applied in routine laboratory analysis in the absence of a single-crystal diffractometer.
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    New triterpenes from Maytenus robusta : structural elucidation based on NMR experimental data and theoretical calculations.
    (2012) Sousa, Grasiely Faria de; Duarte, Lucienir Pains; Alcântara, Antônio Flávio de Carvalho; Silva, Grácia Divina de Fátima; Vieira Filho, Sidney Augusto; Miranda, Roqueline Rodrigues Silva de; Oliveira, Djalma Menezes de; Takahashi, Jacqueline Aparecida
    Leaves of Maytenus robusta (Celastraceae) were subjected to phytochemical investigation mainly directed at the isolation of pentacyclic triterpenes. The compounds friedelin (1), β-friedelinol (2), 3-oxo-21β-H-hop-22(29)-ene (7), 3,4-seco-friedelan-3,11β- olide (8), 3β-hydroxy-21β-H-hop-22(29)-ene (9), 3,4-seco-21β-H-hop-22(29)-en-3-oic acid (10), 3,4-seco-friedelan-3-oic acid (11), and sitosterol were identified in the hexane extract of M. robusta leaves. Compounds 8 and 9 are described herein for the first time. The structure and stereochemistry of both compounds were experimentally established by IR, HRLC-MS, and 1D (1H, 13C, and DEPT 135) and 2D (HSQC, HMBC and COSY) NMR data and supported by correlations with carbon chemical shifts calculated using the DFT method (BLYP/6-31G* level). Compounds 7 and 10 are also described for the first time, and their chemical structures were established by comparison with NMR data of similar structures described in the literature and correlations with BLYP/6-31G* calculated carbon chemical shifts. Compound 9, a mixture of 11 and sitosterol, and 3β,11β-dihydroxyfriedelane (4) were evaluated by the Ellman’s method and all these compounds showed acethylcholinesterase inhibitory properties.
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    Photoprotective property and cytotoxicity of polar extracts of three species of Maytenus native to the Southwest of Bahia.
    (2020) Pereira, Rosângela dos Santos; Aguiar, Rosane Moura; Lemos, Gisele da Silveira; Vieira Filho, Sidney Augusto; Oliveira, Djalma Menezes de
    Maytenus acanthophylla, M. rigida and M. truncata (Celastraceae) are used in the traditional medicine of Chapada Diamantina and Southwest Bahia, Brazil. The infusion and decocto of its leaves are used in the treatment of inflammation and gastric disorders. In this context, it is important to identify chemical and biological properties that reinforce this traditional use. The objective of this study was to determine the total phenolic and flavonoid content by the Folin-Ciocalteau method, the photoprotective property by in vitro spectrophotometric method and the acute toxicity by the mortality index of Artemia salina, of polar extracts of these three Maytenus species. It was observed that the species have similar levels of total phenolic and flavonoid. The presence of compounds containing chromophore groups, which absorb radiation in the UV region between 290 and 320 nm, gives the extracts promising sun protection factors. In the tests with A. salina, the median lethal concentration values were high (≥1000.0 μg/mL) indicating the low toxicity of these extracts. The results contribute to the knowledge of the polar extracts of the three Maytenus species of the Southwest of Bahia, to the validation of the therapeutic properties of these plants and opens perspectives of new studies of photoprotection.
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    The triterpenes 3β-Lup-20(29)-en-3-ol and 3β-Lup-20(29)-en-3-yl acetate and the carbohydrate 1,2,3,4,5,6-Hexa-O-acetyl-dulcitol as photosynthesis light reactions inhibitors.
    (2011) Oliveira, Djalma Menezes de; Aguilar, Maria Isabel; Díaz, Beatriz King; Vieira Filho, Sidney Augusto; Duarte, Lucienir Pains; Silva, Grácia Divina de Fátima; Hennsen, Blas Lotina
    Three compounds were isolated from Maytenus acanthophylla Reissek (Celastraceae): the pentacyclic triterpenes lup-20(29)-en-3β-ol (lupeol, 1) and 3β-lup- 20(29)-en-3-yl acetate (2) and the carbohydrate 1,2,3,4,5,6-hexa-O-acetyldulcitol (3); lupeol was also isolated from Xylosma flexuosa. The compounds’ structures were elucidated by spectroscopic and spectrometric analysis. Compound 1 acts as an energy transfer inhibitor, interacting with isolated CF1 bound to thylakoid membrane, and dulcitol hexaacetate 3 behaves as a Hill reaction inhibitor and as an uncoupler, as determined by polarography. Chlorophyll a (Chl a) fluorescence induction kinetics from the minimum yield F0 to the maximum yield FM provides information of the filling up from electrons coming from water to plastoquinone pool with reducing equivalents. In this paper we have examined the effects of compounds 1 and 3 on spinach leaf discs. Compound 1 induces the appearance of a K-band, which indicates that it inhibits the water splitting enzyme. In vivo assays measuring the fluorescence of chl a in P. ixocarpa leaves sprayed with compound 1, showed the appearance of the K-band and the PSII reaction centers was transformed to “heat sinks” or silent reaction centers unable to reduce QA. However, 3 also induced the appearance of a K band and a new band I appears in P. ixocarpa plants, therefore it inhibits at the water splitting enzyme complex and at the PQH2 site on b6f complex. Compounds 1 and 3 did not affect chlorophyll a fluorescence of L. perenne plants.