Browsing by Author "Vera, Ariesny"
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- ItemDetermination of a natural (17β-estradiol) and a synthetic (17α-ethinylestradiol) hormones in pharmaceutical formulations and urine by adsorptive stripping voltammetry(2019) Jose Trivino, Juan; Gomez, Marisol; Valenzuela, Javiera; Vera, Ariesny; Arancibia, VeronicaAn efficient, fast and sensitive method for the determination of 17 beta-estradiol, (E2) and 17 alpha-ethinylestradiol (EE2) in pharmaceutical formulations and in urine was developed and validated using a hanging mercury drop electrode (HMDE), screen printed carbon electrodes (SPCE), and screen printed carbon nanotube electrodes (SPCNTE). Both analyzes are adsorbed on the working electrodes. To obtain sensitive and selective methods, the effects of various parameters such as pH, adsorption potential, and time (E-ads, t(ads)) were optimized. The optimum experimental conditions chosen for the two analyzes were pH: 10.0; E-ads: - 0.60 and t(ads): 30 s, when HMDE was used. Under these conditions, one reduction signal was found at -1.31 V for E2 and two reduction signals at - 0.23 V and -1.20 V for EE2. The detection limits (DLs) were found to be 0.3 mu g L-1 for E2, 14.8 mu g L-1 for EE2 at - 0.23 V, and 9.7 mu g L-1 for EE2 at -1.20 V. On the other hand, in screen printed electrodes E2 and EE2 present oxidation of the phenolic hydroxyl groups at 0.30, 0.31, 0.32, and 0.33 V (pH:10) with DLs of 242, 277; 182, and 191 mu g L-1 for SPCE and SPCNTE, respectively. The method was successfully applied to the determination of these analyzes in Primaquin (R) (E2), Gynera (R) (EE2), spiked urine (with EE2), and urine samples of women who used Tinelle (R) (EE2) as contraceptive drug.
- ItemExperimental and theoretical physicochemical study of a new dispirocompound: 4′-(4-fluorophenyl)-2′,7-dimethyl-1,4-dihydro-3H-dispiro[cyclopent[b]indol-2,5′-[1,2]oxazinan-6′3"-indolin]-2",3-dione(2021) Satheeshkumar, Rajendran; Montecinos, Rodrigo; Vera, Ariesny; Prasad, Karnam Jayarampillai Rajendra; Kaminsky, Werner; Salas, Cristian O.We present Et3N mediated synthesis of a novel dispirocompound from 5-methyl-2-(4'-fluorophenylidine)-1-oxo-1,2,3,8-tetrahydrocyclopent[b]indole, isatin, and sarcosine through 1,3-dipolar cycloaddition reaction. The crystal structure of synthesised compound, 4'-(4-fluorophenyl)-2',7-dimethyl-1,4-dihydro-3H-dispiro[cyclopent[b]indol-2,5'-[1,2]oxazinan-6',3 ''-indolinl-2 '',3-dione is reported. FT-IR, H-1 and C-13 NMR chemical shifts as measured and calculated using B3LYP method with the 6-311G(d,p) basis set in gas phase were found in good agreement. The optimized geometry of the dispirocompound was compared with experimental XRD values. DFT calculations of the molecular electrostatic potential (MEP), Non-covalent interactions and Hirshfeld Surface analysis, Non-linear optical (NLO) properties and frontier molecular orbitals (FMO) identified chemically active sites of the dispirocompound responsible for its chemical reactivity. (C) 2020 Elsevier B.V. All rights reserved.