FBIOyF - Departamento de Química Analítica - Artículos
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Ítem Acceso Abierto Alkylhalovinylboranes: a new class of Diels-Alder dienophiles(Royal Society of Chemistry, 2018-10-02) Pisano, Pablo Luis; Pellegrinet, Silvina Carla; https://orcid.org/0000-0002-6368-9234; https://orcid.org/0000-0001-6854-7377The Diels–Alder reactions of alkylhalovinylboranes have been investigated theoretically and experimentally. Alkylhalovinylboranes presented higher reactivity than the corresponding dialkylvinylboranes. Although endo/exo selectivities were high for the reactions with cyclopentadiene, facial selectivities for the chiral analogues were low. Our results demonstrate that the replacement of an alkyl group on the boron atom by a halogen increases the dienophilicity considerably.Ítem Embargo Preparation and characterization of new salts of tioconazole. Comparison of their dissolution performance(Elsevier, 2024-01-23) Moroni, Aldana Beatriz; Pérez Mayoral, Elena; Lionello, Diego Fernando; Vega, Daniel Roberto; Kaufman, Teodoro Saúl; Calvo, Natalia LorenaTioconazole is an effective antifungal agent with very low solubility in aqueous media, which limits its bioavailability and efficacy. Aiming to overcome the drug limitations by improving the solubility of this active pharmaceutical ingredient, solution precipitation techniques were employed to prepare four new crystalline salts, namely the mesylate, tosylate, maleate (1:1), and fumarate (1:1) hemihydrate. The thermal stabilities, dissolution properties, and structural characteristics of the solids were determined, and the study was extended to compare their properties with the already-known oxalate salt. The structural characterization of the new phases was carried out using a multi-method approach, which included thermal (differential scanning calorimetry and thermogravimetry), diffractometric (powder X-ray diffraction), and spectroscopic (near-infrared and mid-infrared) methodologies. The determination of the melting point of the salts confirmed the findings made by thermal methods. Functional characteristics of the salts, involving their intrinsic dissolution rates were also determined. It was found that the salts exhibited improved thermal stability and that the nature of the counterion modulated their dissolution characteristics. The salts displayed better intrinsic dissolution rates than the free base, to the point of being “highly soluble” according to the Biopharmaceutical Classification System. At pH 4.3, the sulfonic acid derivatives exhibited better dissolution rates than their carboxylic acid-derived counterparts, greatly improved regarding bare tioconazole. The results suggest that the salts have great potential to be used as replacements for the free base; in principle, careful salt selection may help to fulfill each solubility need for the different scenarios where the drug may be used.Ítem Embargo Characterization of the hydrochloride salt hemihydrate as a new salt of the antifungal agent tioconazole(Elsevier, 2023-03-14) Moroni, Aldana Beatriz; Pérez Mayoral, Elena; Lionello, Diego Fernando; Vega, Daniel Roberto; Kaufman, Teodoro Saúl; Calvo, Natalia LorenaTioconazole is an effective antifungal agent, which has a very low solubility in aqueous media, that limits its bioavailability and efficacy. In an effort to overcome the drug limitations by improving its solubility, the hydrochloride salt was prepared in methanolic 1 M HCl and obtained as the hemihydrate, as demonstrated by elemental analysis. Single crystals were grown by slow evaporation from an aqueous 1 M HCl solution and their structure was determined using single-crystal X-ray diffraction at 302 K. The structures resulting from dehydration and further rehydration were also assessed, at 333 and 283 K, respectively. The morphology of the crystal, which exhibited birefringence under polarized light, was verified by hot stage microscopy. The solid was characterized by additional means, including thermal analysis (melting point, differential scanning calorimetry and thermogravimetry), spectroscopic methods (mid infrared, near infrared, 1H, 13C and 15N nuclear magnetic resonance in solution, as well as 13C and 15N solid state with spinning at the magic angle) and X-ray diffraction techniques. Functional evaluation tests, including the intrinsic dissolution rate and the dissolution of powders were also performed. In the intrinsic dissolution rate test, the salt proved to dissolve over 2000 times faster than tioconazole. The results suggest that the new salt has physicochemical and performance properties which may support its use as a replacement of the free base in certain applications, especially where improved dissolution rate, solubility or bioavailability of the drug would be desired.Ítem Embargo Solid-state properties of Nifurtimox. Preparation, analytical characterization, and stability of an amorphous phase(Elsevier, 2023-01-13) Moroni, Aldana Beatriz; Pérez Mayoral, Elena; Lionello, Diego Fernando; Vega, Daniel Roberto; Kaufman, Teodoro Saúl; Calvo, Natalia LorenaNifurtimox (NFX) is a nitrofuran derivative used to treat Chagas disease, a neglected disease caused by the protozoan Trypanosoma cruzi. The drug is very sparingly soluble in aqueous media and no other solid phases of NFX have been reported to date. The preparation of the amorphous mode of NFX is reported, as well as its characterization by hot stage microscopy, thermal (differential scanning calorimetry and thermogravimetric analysis), spectroscopic (solid state nuclear magnetic resonance, mid-infrared, and near-infrared), diffractometric and functional (powder dissolution rate) means. The stability of the new phase was investigated. This was characterized using thermal, spectroscopic, and diffractometric methods, finding out its spontaneous reversion to the crystalline state, as sign of instability. In addition, the amorphous material proved to be sensitive to temperature, pressure, and mechanical stress, all of which accelerated phase conversion. However, it was able to remain stable in a model polymeric amorphous solid dispersion with PEG 4000 for more than one month. An approach for monitoring the conversion of the amorphous phase to its crystalline counterpart under thermal stress by chemometric analysis of mid-infrared spectra at different temperatures is also disclosed.Ítem Embargo Selected aspects of the analytical and pharmaceutical profiles of Nifurtimox(Elsevier, 2023-02-16) Moroni, Aldana Beatriz; Calvo, Natalia Lorena; Kaufman, Teodoro SaúlNifurtimox is a nitroheterocyclic drug employed for treatment of trypanosomiases (Chagas disease and West African sleeping sickness); its use for certain cancers has also been assessed. Despite having been in the market for over 50 years, knowledge of nifurtimox is still fragmentary and incomplete. Relevant aspects of the chemistry and biology of nifurtimox are reviewed to summarize the current knowledge of this drug. These comprise its chemical synthesis and the preparation of some analogues, as well as its chemical degradation. Selected physical data and physicochemical properties are also listed, along with different approaches toward the analytical characterization of the drug, including electrochemical (polarography, cyclic voltammetry), spectroscopic (ultraviolet-visible, nuclear magnetic resonance, electron spin resonance), and single crystal X-ray diffractometry. The array of polarographic, ultraviolet-visible spectroscopic, and chromatographic methods available for the analytical determination of nifurtimox (in bulk drug, pharmaceutical formulations, and biological samples), are also presented and discussed, along with chiral chromatographic and electrophoretic alternatives for the separation of the enantiomers of the drug. Aspects of the drug likeliness of nifurtimox, its classification in the Biopharmaceutical Classification System, and available pharmaceutical formulations are detailed, whereas pharmacological, chemical, and biological aspects of its metabolism and disposition are discussed.Ítem Acceso Abierto Two sides of the same coin: kernel partial least-squares (KPLS) for linear and non-linear multivariate calibration. A tutorial(Elsevier B.V., 2023-08) Allegrini, Franco; Olivieri, Alejandro CésarÍtem Acceso Abierto A critical review on the development of optical sensors for the determination of heavy metals in water samples. The case of mercury(II) ion(American Chemical Society, 2022-11-08) Escandar, Graciela Mónica; Olivieri, Alejandro CésarÍtem Acceso Abierto Design and implementation of the AMIGA embedded system for data acquisition(IOP Publishing, 2021-07-19) Binet, V.; The Pierre Auger collaborationÍtem Acceso Abierto Chromatographic applications in the multi-way calibration field(MDPI, 2021-10) Chiappini, Fabricio A.; Alcaraz, Mirta R.; Escandar, Graciela Mónica; Goicoechea, Héctor Casimiro; Olivieri, Alejandro CésarÍtem Acceso Abierto Simultaneous determination of pesticides in fruits by using second-order fluorescence data resolved by unfolded partial least-squares coupled to residual bilinearization(Hindawi, 2018-10-16) Villar Navarro, Mercedes; Cabezón, Miguel Angel; Damiani, Patricia CeciliaÍtem Acceso Abierto Online third-order liquid chromatographic data with native and photoinduced fluorescence detection for the quantitation of organic pollutants in environmental water(American Chemical Society, 2018-11-20) Pellegrino Vidal, Rocío Belén; Olivieri, Alejandro César; Ibañez, Gabriela Alejandra; Escandar, Graciela MónicaÍtem Acceso Abierto Excitation-emission fluorescence-kinetic data obtained by Fenton degradation. Determination of heavy-polycyclic aromatic hydrocarbons by four-way parallel factor analysis(Elsevier, 2017-04-01) Carabajal, Maira Daniela; Arancibia, Juan Alberto; Escandar, Graciela MónicaÍtem Embargo Recent applications of first- and second-order multivariate calibration to analytical chemistry(AOAC International, 2014-01) Arancibia, Juan Alberto; Damiani, Patricia Cecilia; Ibañez, Gabriela Alejandra; Olivieri, Alejandro CésarÍtem Acceso Abierto Chemometrics-assisted excitation–emission fluorescence spectroscopy on nylon-attached rotating disks. Simultaneous determination of polycyclic aromatic hydrocarbons in the presence of interferences(Elsevier, 2014-09-10) Cañas, Alejandro; Richter, Pablo; Escandar, Graciela MónicaÍtem Acceso Abierto On-line generation of third-order liquid chromatography–excitation-emission fluorescence matrix data. Quantitation of heavy-polycyclic aromatic hydrocarbons(Elsevier, 2017-12-08) Carabajal, Maira Daniela; Arancibia, Juan Alberto; Escandar, Graciela MónicaÍtem Acceso Abierto Second-order advantage with excitation–emission photoinduced fluorimetry for the determination of the antiepileptic carbamazepine in environmental waters(Elsevier, 2013-06-11) Lozano, Valeria Antonella; Escandar, Graciela MónicaÍtem Acceso Abierto Second-order chromatographic photochemically induced fluorescence emission data coupled to chemometric analysis for the simultaneous determination of urea herbicides in the presence of matrix co-eluting compounds(Royal Society of Chemistry, 2014-04-29) Arancibia, Juan Alberto; Escandar, Graciela MónicaÍtem Acceso Abierto Discrimination of Annona muricata and Rollinia mucosa extracts by using multivariate curve resolution and partial least-squares regression of liquid chromatography-diode array data(Brazilian Chemical Society, 2015-11) Afonso, Sabrina; Pisano, Pablo Luis; Silva, Fabiano; Scaminio, Ieda; Olivieri, Alejandro CésarÍtem Acceso Abierto A green method for the quantification of plastics-derived endocrine disruptors in beverages by chemometrics-assisted liquid chromatography with simultaneous diode array and fluorescent detection(Elsevier, 2016-10) Pellegrino Vidal, Rocío Belén; Ibañez, Gabriela Alejandra; Escandar, Graciela MónicaÍtem Acceso Abierto A green-analytical chemistry method for agrochemical-residue analysis in vegetables(Elsevier, 2016-09) Carabajal, Maira Daniela; Arancibia, Juan Alberto; Escandar, Graciela Mónica
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