952 resultados para Natural Product Synthesis
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Propolis is a natural product collected by honeybees and has a large range of pharmacological activity, including antimicrobial, antitumoral, antioxidant and anti-inflammatory. Its use as a popular medicine is increasing all over the world, creating a need for quality control of the commercial products. In this study the levels of calcium and magnesium in commercial hydroalcoholic propolis extracts from varies states of Brazil were determined by atomic absorption flame spectrophotometry and different values were obtained for northern and southern states. This study can be extended to the analysis of metals that are harmful to health. The results showed that the calibration curves were linear over a wide concentration range (0.5-4.0 μg.mL -1 for calcium and 0.05-0.4 μg.mL -1 for magnesium) with good correlation coefficients (0.999 and 0.988, respectively). Good analytical recovery (94%) was obtained. The proposed method showed adequate precision and relative standard deviation lower than 2 %. The method is accurate and precise as well as having advantages such as simplicity and speed.
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This study aimed to determine the effect of sucrose ester on the control of Varroa destructor mite infestation in Africanized honeybees. For the in vitro experiments, the product was tested in bees and mites at five concentrations obtained through dilution in water (T0: 100% distilled water; T1: 0.5%; T2: 1%; T3: 2%; T4: 5%; and T5: 10% sucrose ester).For the field studies, the experimental design was completely randomized, with four treatments and seven replicates, totaling 28 colonies, from which seven were the controls, seven were treated with 0.1% sucrose ester, seven with 0.2% sucrose ester, and seven hives with 0.5% sucrose ester diluted in water. In the in vitro study, the sucrose ester at 0.5% concentration caused mite and bee mortality. In the field tests, the product at 0.2% concentration reduced Varroa destructor infestation in Africanized honeybees and, therefore, may be used as a tool to control this pest. At 0.1, 0.2, and 0.5% concentrations, sucrose ester did not impair the establishment of open and capped brood areas, as well as stored food areas in the hive, suggesting it is not toxic to Africanized honeybees.
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The synergistic effect of lemon seed extract with tert-butylhydroquinone (TBHQ) in soybean oil subjected to thermoxidation by Rancimat was investigated, and the influence of these antioxidants on α-tocopherol degradation in thermoxidized soybean oil. Control, LSE (2,400 mg/kg Lemon Seed Extract), TBHQ (50 mg/kg), Mixture 1 (LSE + 50 mg/kg TBHQ) and Mixture 2 (LSE + 25 mg/kg TBHQ) were subjected to 180°C for 20 h. Samples were taken at time 0, 5, 10, 15 and 20 h intervals and analysed for oxidative stability and α-tocopherol content. LSE and Mixtures 1 and 2 showed the capacity of retarding lipid oxidation when added to soya oil and also contributed to α-tocopherol retention in oil heated at high temperatures. However, Mixtures 1 and 2 added to the oil presented a greater antioxidant power, consequently proving the antioxidants synergistic effect.
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Many Chrysobalanaceae species, in special Licania and Parinari, are widely used in folk medicine to treat several diseases. This review describes some aspects of their ethnopharmacology potential, biological activities and the secondary metabolites reported so far for Chrysobalanaceae. The chemical constituents of this family include triterpenoids, diterpenoids, steroids and phenylpropanoids like flavonoids as well as chromones derivatives. © 2012 Springer Science+Business Media Dordrecht.
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Rhipicephalus sanguineus, commonly known as the brown dog tick, is one of the most widely distributed species of tick. In dogs, it can cause anemia and provide the transmission of pathogenic microorganisms such as Babesia canis, Ehrlichia canis, Hepatozoon canis, Anaplasma platys, and Mycoplasma haemocanis. To man, it can transmit the intracellular parasites Rickettsia rickettsii and Rickettsia conorii, the causative agents of the Rocky Mountain spotted fever in the Americas and Mediterranean and spotted fever in Europe and North Africa. Its control is performed by applying synthetic formulations composed of pyrethroids; however, continued use of these products results in environmental damage and acquisition of resistance. Alternatively, studies with botanical insecticides have been increasingly recurrent. Therefore, this study aimed to test the efficacy of essential oil of Tagetes patula, a ruderal species widely described in the literature for its insecticidal properties, in engorged females of R. sanguineus by the adults immersion test (AIT) and impregnated paper disk test (IPDT). The essential oil used, through gas chromatography coupled to mass spectrometry, revealed the presence of 55 compounds, being the 4-vinyl guaiacol and gamma terpinene the majority ones. The AIT compared to the IPDT was more efficient in inhibiting oviposition of tick; however, the eggs laid by the females submitted to saturated atmosphere with essential oil, from IPDT, not hatched, interrupted their development cycle. Besides being a pioneer work, the results presented here contributes to new researches, aiming the incorporation of essential oil in an acaricide for use in the environment. © 2013 Springer-Verlag Berlin Heidelberg.
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Actually, the most used method to control ticks is synthetic acaricides with neurotoxic action. However, the use of these methods presents inconveniences, such as the contamination of the environment and risks to the host's health due to the residual effects. Thus, several studies have been developed aiming to find alternative ways to control these ectoparasites, such as the use of natural compounds with active ingredients, which act controlling some species of plagues in addition to presenting medicinal properties that are beneficial to humans. The present study aimed to analyze the action of andiroba oil (Carapa guianensis) on the synganglion of Rhipicephalus sanguineus semiengorged females through morphological and cytochemical techniques aiming to verify if this natural product have neurotoxic action as the numerous synthetic acaricides. The results showed that andiroba oil interferes in the synganglion through structural and enzymatic changes, which lead the nervous tissue to apoptotic death involving autophagy. Among these changes was observed the emergence of large empty spaces between the perineurium and the cortical region, vacuolated cortex cells and with cell swelling, neural cells with picnotic nuclei or in initial stage of chromatin margination and neuropile with high structural disorganization. Considering these data, it can be concluded that andiroba seed oil can be used as an alternative method in the control of R. sanguineus ticks due to its neurotoxic action. © 2013 Wiley Periodicals, Inc.
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Osteosarcoma (OSA) is a primary bone neoplasm frequently diagnosed in dogs. The biology of OSA in pet dogs is identical to that of pediatric patients, and it has been considered an excellent model in vivo to study human OSA. Since the individual response to chemotherapy is unpredictable and considering that propolis is a natural product with several biological properties, this work evaluated the cytotoxic action of propolis on canine OSA cells. The primary cell culture of canine OSA was obtained from the tumor of a dog with OSA. Cell viability was assessed after incubation with propolis, 70% ethanol (propolis solvent), and carboplatin after 6, 24, 48, and 72 h. Cell viability was analyzed by the crystal violet method. Data showed that canine OSA cells were sensitive to propolis in a dose- and time-dependent manner and had a distinct morphology compared to control. Its solvent (70% ethanol) had no effect on cell viability, suggesting that the cytotoxic action was exclusively due to propolis. Our propolis sample exerted a cytotoxic effect on canine OSA cells, and its introduction as a possible therapeutic agent in vivo could be investigated, providing a new contribution to OSA treatment. Copyright © 2012 John Wiley & Sons, Ltd.
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A possible immunomodulatory/anti-inflammatory effect of Baccharis dracunculifolia (Bd) and its major compound - caffeic acid (Ca) - on cytokines production (IL-1b, IL-6 and IL-10) by murine macrophages was investigated. Cells were incubated with Bd and Ca, and the inhibitory concentrations were tested before or after macrophages challenge with LPS. Bd and Ca stimulated IL-1b and inhibited IL-6 and IL-10 production. In LPS-challenge protocols, Bd prevented LPS action either before or after LPS challenge, whereas Ca prevented LPS effects only after LPS addition. Bd modulatory action on cytokines production may be at least in part mediated by Ca, since it has been shown to inhibit the transcription factor NF-kB. Further studies are still needed to evaluate Bd efficacy in inflammatory diseases, in order to explore its antiinflammatory activity in vivo. © 2013 Taylor & Francis.
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Research for acaricides with lower toxicity and impact on the environment has been intensified. An alternative would be the use of natural compounds or of synthetic products in lower concentrations than the ones sold commercially. Thus, this study describes the action of andiroba seed oil on the nuclei of the ovary and synganglion cells of Rhipicephalus sanguineus, and presents an analysis of the nuclear morphology of the nervous system cells of this tick species when exposed to permethrin. The results obtained showed that, although no changes have been observed in the genetic material of the ovary cells exposed to the andiroba oil, this compound, as well as permethrin, has neurotoxic action on the females of this species. The damages caused to the physiology of the synganglion, due to the loss of integrity of the genetic material, would result in the impairment of the metabolism of other systems of R. sanguineus ticks. © 2013 Elsevier Ltd.
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Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV
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Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)