Browsing by Subject "Ionic liquids"

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    Clean enzymatic production of flavor esters in Spongelike Ionic Liquids
    (American Chemical Society, 2019-07-02) Alvarez, Elena; Rodríguez, José; Villa Aroca, Rocío; Gómez, Celia; Donaire, Antonio; Villa Aroca, Rocío; Lozano Rodríguez, Pedro; Nieto Cerón, Susana; Bioquímica y Biología Molecular B e Inmunología
    The biocatalytic synthesis of 16 flavor esters was carried out by the direct esterification of aliphatic acids (e.g., acetic, propionic, etc.) with an alcohol (e.g., cinnamyl alcohol, benzyl alcohol, anisyl alcohol, rac-1-phenylethanol, or rac-sulcatol) using hydrophobic ionic liquids (ILs) based on ammonium or imidazolium cations containing a long alkyl side chain (e.g., hexadecyltrimethylammonium bistriflimide, [C16tma][NTf2]) as the reaction medium. As temperature-switchable liquid/solid phases, these ILs behave as spongelike systems (so-called spongelike ionic liquids (SLILs)), which act as excellent monophasic reaction media for the lipase-catalyzed synthesis of flavor esters. Under appropriate selected reaction conditions (e.g., enzyme, substrate molar ratio, nature of the SLIL, etc.), product yields near 100% were obtained for all of the synthesized flavor esters. Because of the unique spongelike properties of these ILs, a separation protocol based on the centrifugation of the solid IL/flavor ester through nylon membranes was successfully used. By means of this approach, the clean separation of all flavor products from the solid reaction media was easily achieved, while the recovered SLIL/biocatalyst system was reused for six consecutive operation cycles with unchanged catalytic performance.
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    Improving anticancer therapy with naringenin-loaded silk fibroin nanoparticles
    (MDPI, 2020-04-10) Fuster, Marta G.; Carissimi, Guzmán; García Montalbán, Mercedes; Víllora Cano, Gloria; Ingeniería Química
    Naringenin (NAR), a flavonoid present in a variety of fruits, vegetables and herbs, exhibits a wide range of pharmacological effects, including anticancer activity. Nevertheless, its application in cancer therapy is limited due to its low bioavailability at the tumour site because of its poor solubility in water and slow dissolution rate. To improve the therapeutic efficacy of NAR, emergent research is looking into using nanocarriers. Silk fibroin (SF), from the Bombyx mori silkworm, is a biocompatible and biodegradable polymer with excellent mechanical properties and an amphiphilic chemistry that make it a promising candidate as a controlled release drug system. The aim of this work is to synthesize naringenin-loaded silk fibroin nanoparticles (NAR-SFNs) by dissolving the SF in the ionic liquid 1-ethyl-3-methylimidazolium acetate, using high-power ultrasounds and rapid desolvation in methanol followed by the adsorption of NAR. The NAR-SFNs were characterized by dynamic light scattering, Fourier transform infrared spectroscopy and thermogravimetric analysis. The drug loading content and encapsulation efficiency were calculated. The drug release profile best fitted a first order equation. The cytotoxicity effects of free NAR, bare silk fibroin nanoparticles (SFNs) and NAR-SFNs were assessed on HeLa and EA.hy926 cells via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results demonstrated the higher in vitro anticancer potential of synthesized NAR-SFNs than that of free NAR in HeLa cancer cells.
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    Ionic liquids as an enabling tool to integrate reaction and separation processes
    (RSC, 2019-10-22) Alvarez, Elena; Porcar, Raul; Garcia-Verdugo, Eduardo; V Luis, Santiago; Lozano Rodríguez, Pedro; Villa Aroca, Rocío; Bioquímica y Biología Molecular B e Inmunología
    The development of advanced processes able to directly provide pure products by integrating chemical transformations, product separation and recovery and reuse of the solvent and the catalytic phases by straightforward and smart approaches, is a key feature to build green chemical processes. The unique properties of ILs, one of the key enabling technologies, can lead, when combined with (bio)catalysts, to amazing synergies not only improving the catalytic efficiency (i.e. improved activity and enantioselectivity, enhanced stability, etc.), but also allowing the design of smarts approaches for product separation (e.g. IL/scCO2 biphasic reactors, membrane reactors, nanodrop systems, microfluidic devices, supported ionic liquid phases, sponge-like ionic liquids, etc.), incorporating the full recovery and reuse of the catalyst and the ILs phase. This tutorial review highlights representative examples of ILs-based systems integrating reaction/separation as a tool for the development of sustainable chemical processes leading to clean and pure chemical products.
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    Polymeric Inclusion Membranes Based on Ionic Liquids for Selective Separation of Metal Ions
    (MDPI, 2023) Hernández-Fernández, Adrián; Iniesta-López, Eduardo; Ginestá-Anzola, Anahí; Garrido, Yolanda; Pérez de los Ríos, Antonia; Quesada-Medina, Joaquín; Hernández-Fernández, Francisco José; Ingeniería Química
    In this work, poly(vinyl chloride)-based polymeric ionic liquid inclusion membranes were used in the selective separation of Fe(III), Zn(II), Cd(II), and Cu(II) from hydrochloride aqueous solutions. The ionic liquids under study were 1-octyl-3-methylimidazolium hexafluorophosphate, [omim+][PF6-] and methyl trioctyl ammonium chloride, [MTOA+][Cl-]. For this purpose, stability studies of different IL/base polymer compositions against aqueous phases were carried out. Among all polymer inclusion membranes studied, [omim+][PF6-]/PVC membranes at a ratio of 30/70 and [MTOA+][Cl-]/PVC membranes at a ratio of 70/30 were able to retain up to 82% and 48% of the weight of the initial ionic liquid, respectively, after being exposed to a solution of metal ions in 1 M HCl for 2048 h (85 days). It was found that polymer inclusion membranes based on the ionic liquid methyl trioctyl ammonium chloride allowed the selective separation of Zn(II)/Cu(II) and Zn(II)/Fe(III) mixtures with separation factors of 1996, 606 and, to a lesser extent but also satisfactorily, Cd(II)/Cu(II) mixtures, with a separation factor of 112. Therefore, selecting the appropriate ionic liquid/base polymer mixture makes it possible to create polymeric inclusion membranes capable of selectively separating target metal ions.