Publications by authors named "Noemi Waksman de-Torres"

An HPLC-UV/FLD method for simultaneous detection of ten antibiotics in surface waters was developed. Antibiotics were extracted from water using solid phase extraction. An Atlantis T3 column was used with acetonitrile and 0.

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Recently, pharmaceutical and personal care products (PPCPs) have received considerable attention because of their increasing use. Analysis of PPCPs presents a significant analytical challenge, with high-performance liquid chromatography (HPLC) in reversed-phase mode, as the most widely used analytical technique. To facilitate the optimization of the procedures that are applied in the early stages of sample preparation, a simple and fast HPLC method is proposed in this work for the separation of some PPCPs with a wide range of hydrophilicity.

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Background: Oxidative stress and the inflammatory process are involved in ischemia-reperfusion (I/R) injury. Juglans mollis has been reported as having antioxidant activity, which could attenuate the damage caused by I/R. We evaluated whether a methanolic extract of Juglans mollis (JM) exhibits nephroprotective activity in a Wistar rat model of I/R injury.

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Predicting the activity of new chemical compounds over pathogenic microorganisms with different metabolic reaction networks (MRN ) is an important goal due to the different susceptibility to antibiotics. The ChEMBL database contains >160 000 outcomes of preclinical assays of antimicrobial activity for 55 931 compounds with >365 parameters of activity (MIC, IC, etc.) and >90 bacteria strains of >25 bacterial species.

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The antioxidant, antimicrobial, antiproliferative, and enzyme inhibitory properties of five extracts from aerial parts of Epling ex Munz were examined to assess the prospective of this plant as a source of natural products with therapeutic potential. These properties were analyzed by performing a set of standard assays. The extract obtained with dichloromethane showed the most variety of components, as they yielded promising results in all completed assays.

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Background: Microscale in vitro assays are fast, simple, and inexpensive, with reduced reagent quantities, waste, and experimental animal use. However, they have low reproducibility and low correlation with the results of in vivo models, possibly due to differences in precision and accuracy in methodologies between laboratories.

Objective: The objective was the optimization and validation of an in vitro assay, carried out on microscale, to assess the inhibition of α-glucosidase activity, which is indicative of antihyperglycemic activity.

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The plants examined in this study have previous biological activity reports indicating the possibility of found activity against herpes and cancer cell. The aim of this contribution was to carry out a screening of (Juglandaceae), (Lauraceae), (Rubiaceae), (Lamiaceae), (Lamiaceae), (Rhamnaceae), (Asteraceae) y (Ranunculaceae), against HeLa cells, VHS-1 and VHS-2. The method MTT was used to determine the 50% cytotoxic concentration (CC), in Vero and HeLa cell lines.

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Background: The search for new natural or synthetic products with antioxidant activity is commonly based on methods that involve reduction of either 2,2-diphenyl-1-picrylhydrazyl (DPPH) or 2-2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS). However, the reported values of the effective concentrations are highly variable, even in controls. Herein, we optimize and validate both meth-ods of determining antiradical activity.

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Severe fungal infections, particularly those caused by Candida spp, have increased in recent decades and are associated with an extremely high rate of morbidity and mortality. Since plants are an important source of potentially bioactive compounds, in this work the antifungal activity of the methanol extracts of 10 plants (Acacia rigidula, Buddleja cordata, Cephalanthus occidentalis, Juglans nigra, Parkinsonia aculeata, Parthenium hysterophorus, Quercus canbyi, Ricinus communis, Salvia coccinea and Teucrium bicolor) were evaluated. The activity was evaluated according to the micro dilution assay described in CLSI M27-A protocol using some clinical isolates of different species of Candida (C.

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Hamelia patens is widely used in the traditional medicine of Mexico and Central America for the treatment of illnesses associated with inflammatory processes. In this study, antioxidant and hepatoprotective activity were assayed on the methanolic crude (ME), hexane (HE), ethyl acetate (AE), and butanol (BE) extracts of H. patens.

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The dengue virus is transmitted by Aedes aegypti. Several plants are used to control this mosquito. In the present study the chemical composition of the essential oils of Ruta chalepensis, Zanthoxylum fagara and Thymus vulgaris were analyzed, and their activities against larvae of two A.

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Opportunistic mycoses increase the morbidity and mortality of immuno-compromised patients. Five Candida species have been shown to be responsible for 97% of worldwide cases of invasive candidiasis. Resistance of C.

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Seventeen new derivatives of the natural diterpene leubethanol, including some potential pro-drugs, with changes in the functionality of the aliphatic chain or modifications of aromatic ring and the phenolic group, were synthesized and tested in vitro by the MABA technique for their activity against the H37Rv strain of Mycobacterium tuberculosis. Some compounds showed antimycobacterial selectivity indices higher than leubethanol.

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There have been no reports of antifungal activity and composition of extracts from Thymus vulgaris, Rosmarinus officinalis or Origanum majorana from northeastern México. Antifungal activity of these oils against Trichophyton rubrum, Trichophyton tonsurans, Trichophyton mentagrophytes, Microsporum gypseum, Microsporum canis and Epidermophyton floccosum was measured by diffusion assay. Additionally, antibacterial and antioxidant activities were evaluated.

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A chromatographic method was implemented and validated for the simultaneous determination of antimicrobials proposed for the treatment of mycetoma: three fluoroquinolones: ciprofloxacin, moxifloxacin and sparfloxacin; two oxazolidinones: DA-7157 (DA2; torezolid) and its prodrug DA-7218 (DA1). Separation of analytes was achieved on an Atlantis dC18 column (150 × 4.6 mm i.

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The essential oils from Magnolia grandiflora and Chrysactinia mexicana leaves, and from Schinus molle leaves and fruit, were characterized by gas chromatography/flame-ionization detection and gas chromatography/mass spectrometry. Twenty-eight compounds from M. grandiflora leaves were identified (representing 93.

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Bioassay-guided fractionation of the minor active fractions obtained from the root bark of Leucophyllumfrutescens (Berl.) I. M.

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Twenty-five derivatives of the natural diterpene leubethanol, including several potential pro-drugs, with changes in the functionality of the aliphatic chain or modifications of the phenolic group, were synthesized and tested in vitro by the MABA technique for their activity against the H37Rv strain of Mycobacterium tuberculosis. Several compounds showed antimycobacterial potencies similar to that of the lead compound and two of them displayed higher selectivity indexes.

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The determination of the antioxidant activity of Turnera diffusa using partial least squares regression (PLSR) on chromatographic data is presented. The chromatograms were recorded with a diode array detector and, for each sample, an enhanced fingerprint was constructed by compiling into a single data vector the chromatograms at four wavelengths (216, 238, 254 and 345 nm). The wavelengths were selected from a contour plot, in order to obtain the greater number of peaks at each of the wavelengths.

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The essential oil of Chrysactinia mexicana retrieved from the root bark was characterized by gas chromatography coupled to a mass detector. The compounds silphiperfol-5-ene, 7-epi- silphiperfol-5-ene, modheph-2-ene, alpha-isocomene, beta-isocomene and methyl-linoleate were identified. The principal compound (76.

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Background: Centaurea americana, Krameria ramosissima, Juglans mollis and Turnera diffusa are used by traditional healers in the northeastern region of Mexico to protect against liver damage. However, the hepatoprotective properties of these plants have not been investigated scientifically. This study reports on the protective effects of these plants using an in vitro assay.

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In the present contribution, the partial least squares (PLS) method was used to establish a correlation between the antioxidant activity (obtained by DPPH assay) and chromatographic profiles of TURNERA DIFFUSA extracts. Chromatograms were obtained using HPLC-DAD. A model was constructed using 40 samples with 2550 X variables corresponding to the responses obtained at different times; the Y variables consisted of experimental values of antioxidant activity of each extract (measured as EC₅₀).

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Damiana is a shrub used as a dietary supplement and as an additive in several foods. This report presents the first validated analytical method for QC of products made from damiana. Through bioassay-guided fractionation, the compound showing the best antioxidant activity, determined using 2,2-diphenyl-1-picryl-hydrazyl assay in TLC, was purified and identified as 8-C-beta-[6-deoxy-2-O-(alpha-1-rhamnopyranosyl)-xylo- hexopyranos-3-uloside] (Cl50 5.

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Traditional medicine has a key role in health care worldwide. Obtaining scientific information about the efficacy and safety of the plants from our region is one of the goals of our research group. In this report, 17 plants were selected and collected in different localities from northeast Mexico.

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