Publicaciones 2011-2020

@article{RN286,
title = {Secondary Metabolites in Ramalina Terebrata Detected by Uhplc/Esi/Ms/Ms and Identification of Parietin as Tau Protein Inhibitor},
author = { A. Cornejo and F. Salgado and J. Caballero and R. Vargas and M. Simirgiotis and C. Areche},
url = {/brokenurl#<Go to ISI>://WOS:000382337900115},
doi = {10.3390/ijms17081303},
issn = {1422-0067},
year = {2016},
date = {2016-01-01},
journal = {International Journal of Molecular Sciences},
volume = {17},
number = {8},
abstract = {Liquid chromatography coupled with mass spectrometry is an outstanding methodology for fast analysis of phenolic compounds in biological samples. Twenty two compounds were quickly and accurately identified in the methanolic extract of the Antarctic lichen Ramalina terebrata for the first time using ultra high pressure liquid chromatography coupled with photodiode array detector and high resolution mass spectrometry (UHPLC-PDA-Q/Orbitrap/MS/MS). In addition, the extract and the four compounds isolated from this species were tested for the inhibitory activity of tau protein aggregation, which is a protein involved in Alzheimer's disease (AD). All compounds showed null activity with the exception of parietin, which it was able to inhibit aggregation process of tau in a concentration range between 3 mu g/mL (10 mu M) to 28 mu g/mL (100 mu M). In addition, we show how parietin interact with tau (306)VQIVYK(311) hexapeptide inside of the microtubule binding domain (4R) with the help of molecular docking experiments. Finally, the constituents present in the methanolic extract could possibly contribute to the established anti-aggregation activity for this extract and this in-depth analysis of the chemical composition of R. terebrata could guide further research into its medicinal properties and potential uses.},
keywords = {alzheimer's alzheimers-disease, biological disease, docking, evaluation, fibril filaments, formation helical lichen lichens, liquid-chromatography, mass-spectrometry, molecular paired parietin, phenolic-compounds, protein, ramalina, tau uhplc-q/orbitrap/ms/ms, uhplc/ms, xanthoria-parietina},
pubstate = {published},
tppubtype = {article}
}

@article{RN287,
title = {Phenolic Compounds in Chilean Mistletoe (Quintral, Tristerix Tetrandus) Analyzed by Uhplc-Q/Orbitrap/Ms/Ms and Its Antioxidant Properties},
author = { M.J. Simirgiotis and C. Quispe and C. Areche and B. Sepulveda},
url = {/brokenurl#<Go to ISI>://WOS:000373802200140},
doi = {10.3390/molecules21030245},
issn = {1420-3049},
year = {2016},
date = {2016-01-01},
journal = {Molecules},
volume = {21},
number = {3},
abstract = {Mass spectrometry has become a method of choice to characterize bioactive compounds in biological samples because of its sensitivity and selectivity. Hybrid ultra-HPLC hyphenated with Orbitrap mass analyzer is an innovative state of the art technology that allows fast and accurate metabolomic analyses. In this work the metabolites of a Chilean mistletoe endemic to the VIII region of Chile were investigated for the first time using UHPLC mass analysis (UHPLC-PDA-HESI-Orbitrap MSn). The anthocyanins, together with the non-pigmented phenolics were fingerprinted and correlated with the antioxidant capacities measured by the bleaching of the DPPH radical, the ferric reducing antioxidant power (FRAP), the superoxide anion scavenging activity assay (SA), and total content of phenolics, flavonoids and anthocyanins measured by spectroscopic methods. Six anthocyanins were identified, and among them, the 3-O-glycosides of delphinidin and cyanidin were the major ones. In addition, several phenolic acids (including feruloylquinic acid, feruloyl glucose, chlorogenic acid) and several flavonols (luteolin, quercetin, apigenin, isorhamnetin and glycoside derivatives) were also identified. The mistletoe leaves showed the highest antioxidant activity as measured by the DPPH radical bleaching, ferric reducing antioxidant power and superoxide anion scavenging activity tests (13.38 +/- 0.47 mu g/mL, 125.32 +/- 5.96 mu molTE/g DW and 84.06 +/- 4.59 at 100 mu g/mL, respectively).},
keywords = {anthocyanins, antioxidants, bioactive chile, components, del esi-ms, extracts flavonoids, fruits, hplc-dad, hplc-ms, l., liquid-chromatography, mass-spectrometry, medicinal-plants, muerdago, northern phenolic quintral ultra},
pubstate = {published},
tppubtype = {article}
}

@article{RN207,
title = {Binding of Phenols with Amphipathic Cationic Polyelectrolytes},
author = { H. Rios and G.A. Collio and M. Urz\'{u}a and V. Vargas},
url = {/brokenurl#<Go to ISI>://WOS:000331602300006},
doi = {10.1080/00222348.2013.845067},
issn = {0022-2348},
year = {2014},
date = {2014-01-01},
journal = {Journal of Macromolecular Science Part B-Physics},
volume = {53},
number = {3},
pages = {428-439},
abstract = {The association of phenols, such as p-cresol, tribromophenol, and trichlorophenol, with several amphipathic poly (n-alkylmethyldiallylammonium) chlorides in aqueous solution was studied by ultrafiltration. The n-alkyl residues were octyl, decyl, and dodecyl and the binding degrees were significantly higher than those found with the hydrophilic poly (diallyldimethylammonium) chloride. The results agreed well with the Satake and Yang's treatment and Hill's empirical equation for the association process, thereby revealing, in both cases, an increasing cooperative effect as the polyelectrolyte side chain increased in length for the same phenol, and when the hydrophobic nature of the phenol increased for the same kind of polyelectrolyte. From the phenomenological association constants, the estimated molar standard free energies of association ranged from -19kJmol(-1), for the more hydrophilic phenoxide-polyelectrolyte pair, to -28kJmol(-1) for the more hydrophobic pairs. The main result is that the amphipathic nature of these polyelectrolytes makes them efficient systems to trap anionic contaminants, better than hydrophilic flocculants.},
keywords = {amphipathic aqueous-solution, association, binding, cooperative decyl, liquid-chromatography, micelles, partition-coefficients, phenols, polyelectrolytes, salts solubilization, sulfonates},
pubstate = {published},
tppubtype = {article}
}

@article{RN174,
title = {Determination and Co-Estimate of the Chlormadinone Acetate and 17 Alpha-Ethinyl Estradiol in Pharmaceutical Formulation and Drinking Water Samples by Digital Derivative Spectophotometry},
author = { C. Soto and R. Otipka and M.I. Toral and D. Pino and D. Contreras and J. Yanez},
url = {/brokenurl#<Go to ISI>://WOS:000342613100019},
doi = {10.4067/S0717-97072014000200019},
issn = {0717-9707},
year = {2014},
date = {2014-01-01},
journal = {Journal of the Chilean Chemical Society},
volume = {59},
number = {2},
pages = {2485-2489},
abstract = {In this work are presented two methods for the simultaneous determination of 17 alpha-ethinylestradiol (EEL) and chlormadinone acetate (CMA) by second order derivative spectrophotometry., The first analytical method proposed is based in the dissolution and extraction of both drugs in acetonitrile. The solution was directly evaluated by second order derivative spectrophotometry with a smoothing factor of 8,000 and a scale factor of 10,000. The determination of EEL and CMA was carried out to 296,6 and 291.8 nm, respectively. The detection limits (3.3 sigma criterion) for EEL and CMA were 6.9 x 10(-7) and 9.8 x 10(-8) mol/L, respectively., Furthermore, a study of the effect of the excipients containing in the pharmaceutical formulation was included. Polyvidone presents greater tendency to produce interference, but its spectral bands are located between 215 and 240 nm, so these bands do not interferes spectrally in the simultaneous determination of EEL and CMA. Both drugs were extracted from the pharmaceutical formulation with acetonitrile, obtaining a good recovery relative to the nominal content., The second method is a screening method and was applied in fortified drinking water. In this method, drugs were extracted in chloroform, which was then removed with N-2 and the residue was redissolved in acetonitrile. Due to the difference in the procedure in relation to the pharmaceutical formulation a new analytical parameters were obtained. For EEL this parameters were very similar to those obtained directly in solution, however these were higher for CMA, which could be attributed to that under these conditions was found a higher standard deviation of the blank. Recoveries of fortified samples were 81.8 +/- 1.5% and 101.1 +/- 0.73% for EEL and CMA, respectively.},
keywords = {alpha-ethinyl chlormadinone derivative electrode estradiol, ethinylestradiol, formulations, gestodene, human least-squares, liquid-chromatography, mass-spectrometry, method, oral-contraceptives, performance pharmaceutical plasma, screening spectrophotometry, tandem},
pubstate = {published},
tppubtype = {article}
}

@article{RN115,
title = {Variations in the Chemical Profile and Biological Activities of Licorice (Glycyrrhiza Glabra L.), as Influenced by Harvest Times},
author = { J. Cheel and L. Tumova and C. Areche and P. Van Antwerpen and J. Neve and K. Zouaoui-Boudjeltia and A.S. Martin and I. Vokral and V. Wsol and J. Neugebauerova},
url = {/brokenurl#<Go to ISI>://WOS:000316339400032},
doi = {10.1007/s11738-012-1174-9},
issn = {0137-5881},
year = {2013},
date = {2013-01-01},
journal = {Acta Physiologiae Plantarum},
volume = {35},
number = {4},
pages = {1337-1349},
abstract = {This study investigates the variations in the chemical profile, free radical scavenging, antioxidant and gastroprotective activities of licorice extracts (LE) from plants harvested during the months of February to November. Correlations between biological properties and the chemical composition of LE were also investigated. The results showed that the total contents of phenols, flavonoids and tannins in LE varied at different harvest times. Liquiritin and glycyrrhizin, the major components of LE, varied in the range of 28.65-62.80 and 41.84-114.33 mg g(-1), respectively. The relative proportion of glycyrrhizin derivative (3), glabridin (4), glabrene (5) and liquiritigenin derivative (6), varied in the range of 0.88-11.38 %, 1.86-10.03 %, 1.80-18.40 % and 5.53-16.31 %, respectively. These fluctuations correlated positively with changes in the antioxidant and free radical scavenging activities of licorice. In general, the samples from May and November showed the most favorable free radical scavenging and antioxidant effects, whereas the best gastroprotective effect was in May. Liquiritin and glycyrrhizin, the major constituents in the February and May LE, appeared to contribute to the superoxide radical scavenging and gastroprotective effects. Glabridin and glabrene, the compounds with the highest relative proportion in the November LE, accounted for the antioxidant and DPPH scavenging activities of licorice. It is concluded that the chemical profile of licorice quantitatively varied at different harvest times and these fluctuations determined changes in its bioactivities. These data could pave the way to optimize harvesting protocols for licorice in relation with its health-promoting properties.},
keywords = {activity, antioxidant constituents, extracts, flavonoids, fruits harvest hplc, ldl licorice, liquid-chromatography, myeloperoxidase, oxidation, performance roots, seasonal-variations, times},
pubstate = {published},
tppubtype = {article}
}