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Dziagwa-Becker M.M.,Institute of Soil Science and Plant Cultivation | Marin Ramos J.M.,University Jaume astellon | Topolski J.K.,Institute of Soil Science and Plant Cultivation | Oleszek W.A.,Institute of Soil Science and Plant Cultivation
Analytical Methods

A robust and sensitive method for identification (quantification and confirmation) of 19 free amino acids in the plant matrix, Stellaria media, based on liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS), with a triple quadrupole analyser, has been developed. Regarding MS optimization, flow injection analysis (FIA) was used in scan and selected reaction monitoring (SRM) mode. The collision energies optimized varied from -12 to -39 eV. The acquisition of three MS/MS transitions for most of the compounds allowed the accurate confirmation of these analytes, which was supported by the accomplishment of ion intensity ratios and retention time as compared with the corresponding standards. The use of a Phenomenex EZ:faast™ Free (Physiological) Amino Acid kit speeds up the sample preparation immeasurably. Nineteen amino acids were separated within 18 minutes on a reverse-phase column under a gradient stepwise programme using 10 mM ammonium formate both in water and methanol. The detection limit (LOD) for free amino acids varied from 0.4 to 9.1 pmol mL-1, except for asparagine amounting to 3000 pmol mL-1. The quantification precision (RSD) of free amino acids for intra- and interday assays was 0.05-19% and 0.2-19%, respectively, but for most of the compounds, it did not exceed 5%. The optimized and validated method was subsequently utilized for free amino acid identification in weed collected from field locations in Poland. This journal is © The Royal Society of Chemistry. Source

Vilanova C.,University Jaume astellon | Diaz-Oltra S.,University Jaume astellon | Murga J.,University Jaume astellon | Falomir E.,University Jaume astellon | And 2 more authors.
Bioorganic and Medicinal Chemistry Letters

Abstract A small group of hybrid molecules composed of a colchicine moiety and a pironetin analogue fragment have been investigated for their ability to inhibit the expression of the VEGF, hTERT and c-Myc genes. The VEGF gene is involved in the generation of the vascular endothelial growth factor (VEGF) and thus in the angiogenic process whereas the two latter ones are related to the activation of telomerase. All three genes therefore may be of paramount importance in the cancer generation process. It has been found that colchicine and some of its derivatives display a measurable ability to inhibit the expression of the VEGF and the two other telomerase-related genes. In the case of some of the hybrids, the available data point to the colchicine fragment being responsible for the observed biological activities. It is the first time that the last biological feature has been reported for colchicine or derivatives thereof. © 2015 Elsevier Ltd. Source

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