14 research outputs found

    HPLC-DAD/TOF-MS Chemical Compounds Analysis and Evaluation of Antibacterial Activity of Aristolochia longa Root Extracts

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    The present study aimed to determine the phenolic compounds of Arislolochia Ion& root extracts and to evaluate their antibacterial activities on multiresistant strains. Phytochemical analysis revealed the presence of flavonoids, tannins, terpenoids, and alkaloids. The HPLC-DAD analysis of A. longa extracts showed the presence of several major bioactive compounds such as ferulic acid, 4-hydroxycinnamic acid, citric acid, and quinic acid. The agar diffusion method was used for the sensitivity test, while minimal inhibitory concentration (MIC) and minimal bactericidal concentration values were determined by microdilution assay. Different tests were carried out on 3 clinical multiresistant strains and 3 reference strains. The diameter of inhibition of Staphylococcus aureus ATCC 25923 induced by the ethyl acetate fraction at 200 mg/mL was 25 +/- 1 mm. Moreover, Escherichia coli ATCC 29522 showed a great sensitivity toward all the concentrations tested. The MICs of the active extracts vary between 12.5 and 100 mg/mL with a bacteriostatic effect on Pseudomonas aemginosa ATCC 27853, Enterococcus faecalis, and S. aureus ATCC 25923.Peer reviewe

    19F NMR investigation of the Pb1-xMgxF2 solid solution

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    An 19F source NMR investigation of the Pb1−xMgxF2 solid solution is undertaken as a function of temperature. Several F− ion sublattices are identified, they become progressively mobile on the NMR time scale at increasing temperature. Clusters are proposed from the composition dependence of the anionic distribution determined by deconvolution of the low temperature 19F source NMR spectra. Temperature dependence of the jump frequency shows the existence of several F− ion motions corresponding to exchange motions inside and between fluoride sublattices

    Electrical characterization of the fluoride K3Fe5F15 by impedance spectroscopy

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    The ac response of the fluoride K3Fe5F15 has been investigated over the temperature range 293-773K using impedance spectroscopy. Impedance spectra show a curve that can be considered as an envelop of two depressed semicircles corresponding to bulk and grain boundary properties, and the modulus complex show two almost arcs..

    Electrical characterization of the fluoride K3Fe5F15 by impedance spectroscopy

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    The ac response of the fluoride K3Fe5F15 has been investigated over the temperature range 293-773K using impedance spectroscopy. Impedance spectra show a curve that can be considered as an envelop of two depressed semicircles corresponding to bulk and grain boundary properties, and the modulus complex show two almost arcs..

    Short-range order and diffusion processes in the Na1-xBixF1+2x anion-excess solid solution

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    The F− diffusion processes within the anion-excess solid solution Na1−xBixF1+2x with fluorite-type structure have been studied by 19F-NMR investigation. Two types of fluoride ions, Fn and F′, are distinguished in the 19F-NMR spectra of rigid lattice at low temperature (T=175 K) and the distribution of fluoride ions among the two sites is determined by deconvolution of the experimental spectra. The short-range order in these materials is analogous to the clustering process observed in the K1−xBixF1+2x solid solution. It corresponds to an order between cubic entities and cubooctaedral clusters. Two diffusion mechanisms are identified on both sides of a Tr temperature. The first one at TTr to an F− exchange between cubic and cubooctaedral clusters

    Characterization of the physico-chemical properties of the natural habitat and in vitro culture effects on the biochemistry, proliferation and morphology of Lemna minuta

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    Abstract In this study, the ecological conditions of the natural habitat of Lemna minuta Kunth in Morocco were investigated, and the impact of five synthetic growth media (Murashige-Skoog (MS), Schenk-Hildebrand (SH), Hoagland medium (HM), 10X Algal Assay Procedure (AAP), and Swedish Standard Institute medium (SIS)) on the morphophysiological and biochemical parameters was analysed. The morphophysiological parameters included root length, frond surface area, and fresh weight, while the biochemical parameters included photosynthetic pigments, carbohydrates, and protein content. The study was conducted in vitro in two phases: an uncontrolled aeration system (Phase I) and a controlled aeration system (Phase II). The results showed that the pH, conductivity, salinity, and ammonium levels in the natural habitat were within the optimal range for duckweed growth. The measured orthophosphate concentrations were higher compared to previous observations, while the recorded chemical oxygen demand values were low. The study also revealed a significant effect of the culture medium composition on the morphophysiological and biochemical parameters of the duckweed. The fresh weight biomass, relative growth rate in fronds, relative growth rate in surface area, root length, protein content, carbohydrates, chlorophyll (a), chlorophyll (b), total chlorophyll, carotenoids, and the chlorophyll (a/b) ratio were all affected by the culture medium. The most accurate regression models described the growth index GI(F) based on time and in vitro culture conditions in both phases. In Phase I, the best models for MS, SIS, AAP, and SH media were linear, weighted quadratic, cubic, and weighted cubic, respectively. In Phase II, the best models for all growth media were linear. The time coefficients (in days) for Phase II were 0.321, 0.547, 1.232, 1.470, and 0.306 for AAP, HM, MS, SH, and SIS, respectively. Comparing the morphophysiological and biochemical parameters of fronds from different media and analysing the regression model results showed that the SH and MS media were the best among the tested media for the in vitro culture of L. minuta in controlled aeration conditions. However, further research is needed to develop new synthetic media that best promote the growth and maintenance of this duckweed in long-term culture

    Evaluation of In Vitro Antioxidant and Antidiabetic Activities of Aristolochia longa Extracts

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    Oxidative stress plays a major role in diabetic physiopathology; hence, the interest of using natural antioxidants as therapeutic tools exists. The aim of this study was the evaluation of in vitro antioxidant activity and inhibitory potential of organic extracts from Aristolochia longa roots against key enzymes linked to hyperglycemia. Antioxidant activity was performed using 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals and ferric reducing/antioxidant power (FRAP) methods. The α-Glucosidase and β-Galactosidase inhibitory activities were investigated using an in vitro model. Moreover, phytochemical analysis of tested extracts was carried out. The aqueous fraction of this herb exhibited the highest antioxidant activity for both DPPH and ABTS methods, IC50=125.40±2.40 μg/mL and IC50=65.23±2.49 μg/mL, respectively. However, the ethyl acetate fraction possessed the strongest inhibitory effect towards α-Glucosidase (IC50=1.112±0.026 mg/mL). Furthermore, the result showed high levels of phenolic content. The results showed that this plant could be a significant source of medically important natural compounds

    Effect of oxygen on short-range order in the Ba1-xBixF2+x solid solution

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    Various compositions within the range of the fluorite-type solid solution in the BaF2–BiF3–BiOl.5 system are investigated by impedance spectroscopy. This study is carried out along two lines of compositions: δ1, corresponding to the Bal−2z/3Bi2z/3F2+4z/3Oz solid solution, where z is the oxygen rate; and δ2, corresponding to the Bal−xBixF2+x−0.30O0.15 solid solution, where x is the bismuth rate. An approach to the nature of the fluorine–oxygen order is proposed which derives from the clustering process in the Bal−xBixF2+x fluoride solid solution
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