scholarly journals Synthesis of Purine-Based Ionic Liquids and Their Applications

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6958
Author(s):  
Ana R. F. Carreira ◽  
Telma Veloso ◽  
Nicolas Schaeffer ◽  
Joana L. Pereira ◽  
Sónia P. M. Ventura ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Sodium Sulfate ◽  
Water Solubility ◽  
Chemical Properties ◽  
Aqueous Solubility ◽  
Salting Out ◽  
Good Thermal Stability ◽  
Solubility Enhancers ◽  
Biphasic Systems ◽  
As Solubility

Bio-based ionic liquids (ILs) are being increasingly sought after, as they are more sustainable and eco-friendly. Purines are the most widely distributed, naturally occurring N-heterocycles, but their low water-solubility limits their application. In this work, four purines (theobromine, theophylline, xanthine, and uric acid) were combined with the cation tetrabutylammonium to synthesize bio-based ILs. The physico–chemical properties of the purine-based ILs were characterized, including their melting and decomposition temperatures and water-solubility. The ecotoxicity against the microalgae Raphidocelis subcapitata was also determined. The ILs show good thermal stability (>457 K) and an aqueous solubility enhancement ranging from 53- to 870-fold, in comparison to their respective purine percursors, unlocking new prospects for their application where aqueous solutions are demanded. The ecotoxicity of these ILs seems to be dominated by the cation, and it is similar to chloride-based IL, emphasizing that the use of natural anions does not necessarily translate to more benign ILs. The application of the novel ILs in the formation of aqueous biphasic systems (ABS), and as solubility enhancers, was also evaluated. The ILs were able to form ABS with sodium sulfate and tripotassium citrate salts. The development of thermoresponsive ABS, using sodium sulfate as a salting-out agent, was accomplished, with the ILs having different thermosensitivities. In addition, the purine-based ILs acted as solubility enhancers of ferulic acid in aqueous solution.

Dynamic Kinetic Resolution of Sec-Alcohols in Ionic Liquids/Supercritical Carbon Dioxide Biphasic Systems

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Pedro Lozano ◽  
Teresa De Diego ◽  
Michel Vaultier ◽  
Jose L Iborra
Keyword(s):  
Carbon Dioxide ◽  
Ionic Liquids ◽  
Supercritical Carbon Dioxide ◽  
Kinetic Resolution ◽  
Immobilized Lipase ◽  
Enzymatic Catalysis ◽  
Chemical Properties ◽  
Dynamic Kinetic Resolution ◽  
Biphasic Systems ◽  
Supercritical Carbon

Supercritical fluids and ionic liquids are neoteric solvents that can be used as non-conventional reaction media for enzymatic catalysis under optimised conditions. These solvents exhibit many different physical and chemical properties, but have two cross-points: they are not-miscible and can be easily separated from substrates and products, and they can be reused. As supercritical carbon dioxide (scCO2) can dissolve in the ionic liquid (IL) phase (up to 0.7 mole fraction), a new concept of biphasic bioreactors for Fine Chemicals syntheses may be developed by using both enzyme and chemical catalysts "immobilized" into the IL phase, and substrates transported by the scCO2 phase. The system was tested for the continuous chemoenzymatic dynamic kinetic resolution (DKR) of rac-1-phenylethanol in IL/scCO2 by using simultaneously immobilized lipase (Novozym 435) and acid zeolites catalysts at 50°C and 100 bars, providing good yields (up 98.0 %) for R-phenylethyl propionate ester with excellent enantioselectivity (up to 97.3 %), and without any activity loss after 14 days of operation.

scholarly journals Salting-out in Aqueous Solutions of Ionic Liquids and K3PO4: Aqueous Biphasic Systems and Salt Precipitation

2007 ◽  
Vol 8 (8) ◽  
pp. 736-748 ◽  
Author(s):  
Vesna Najdanovic-Visak ◽  
José Lopes ◽  
Zoran Visak ◽  
J. Trindade ◽  
Luís Rebelo
Keyword(s):  
Ionic Liquids ◽  
Aqueous Solutions ◽  
Salt Precipitation ◽  
Salting Out ◽  
Aqueous Biphasic Systems ◽  
Aqueous Biphasic ◽  
Biphasic Systems

scholarly journals Design and Development of Spray-Dried Microsystems to Improve Technological and Functional Properties of Bioactive Compounds from Hazelnut Shells

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1273 ◽  
Author(s):  
Tiziana Esposito ◽  
Teresa Mencherini ◽  
Pasquale Del Gaudio ◽  
Giulia Auriemma ◽  
Silvia Franceschelli ◽  
...  
Keyword(s):  
Water Solubility ◽  
Liquid Feed ◽  
Industrial Use ◽  
Critical Characteristics ◽  
Solubility Enhancers ◽  
Hazelnut Shells ◽  
Unpleasant Smell ◽  
By Products ◽  
As Solubility ◽  
Water Dissolution

An extract obtained from hazelnut shells by-products (HSE) has antioxidant and chemopreventive effects on human melanoma and cervical cancer cell lines, inducing apoptosis by caspase-3 activation. A clinical translation is limited by poor water solubility and low bioavailability. Dried plant extracts often show critical characteristics such as sticky/gummy appearance, unpleasant smell, and instability involving practical difficulties in processing for industrial use. A spray drying method has been applied to transform raw HSE in a microparticulate powder. The biopolymeric matrix was based on l-proline as loading carrier, hydroxyethylcellulose in combination with pectin as coating polymers; lecithin and ethanol were used as solubility enhancers. A Hot-Cold-Hot method was selected to prepare the liquid feed. The thus prepared powder showed good technological properties (solid-state, particle dimensions, morphology, and water dissolution rate), stability, and unchanged chemopreventive effects with respect to the unprocessed HSE.

Phosphonium and Ammonium Ionic Liquids with Aromatic Anions: Synthesis, Properties, and Platinum Extraction

2010 ◽  
Vol 63 (3) ◽  
pp. 511 ◽  
Author(s):  
Anja Stojanovic ◽  
Daniel Kogelnig ◽  
Lisa Fischer ◽  
Stephan Hann ◽  
Markus Galanski ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Water Solubility ◽  
Aqueous Media ◽  
Chemical Properties ◽  
Aliquat 336 ◽  
Physico Chemical ◽  
Synthesis Properties ◽  
Aromatic Anions ◽  
Extracting Agents ◽  
Ammonium Ionic Liquids

Several hydrophobic long-chain quaternary ammonium and phosphonium ionic liquids (ILs) with functionalized aromatic anions were prepared following a metathesis route using tricaprylmethylammonium chloride (Aliquat 336) and trihexyl(tetradecyl)phosphonium chloride (Cyphos IL101) as precursors. The incorporation of aromatic anions bearing hydroxy-, methoxy-, thiol-, and thioether functionalities as well as tetraphenylborate anions resulted in an increased chemical stability of the ILs and an alteration of their physico-chemical properties. Furthermore, aromatic anions significantly decreased the water solubility and water uptake of both ammonium and phosphonium-based ILs. Thiol- and thioether ILs were applied for the extraction of platinum from aqueous phase using liquid phase micro-extraction. Time dependent studies showed a rapid elimination of up to 95% platinum after 30 min. With a leaching of the anion <0.01 wt-% into the aqueous media, the evaluated ILs were found to be suitable as extracting agents for platinum from aqueous solutions.

scholarly journals Advances Brought by Hydrophilic Ionic Liquids in Fields Involving Pharmaceuticals

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6231
Author(s):  
Teresa B. V. Dinis ◽  
Francisca A. e Silva ◽  
Fani Sousa ◽  
Mara G. Freire
Keyword(s):  
Drug Delivery ◽  
Ionic Liquids ◽  
Drug Delivery Systems ◽  
Biological Activities ◽  
Aqueous Solubility ◽  
Key Factors ◽  
The Past ◽  
Extraction Performance ◽  
Biphasic Systems ◽  
Selection Of

The negligible volatility and high tunable nature of ionic liquids (ILs) have been the main drivers of their investigation in a wide diversity of fields, among which is their application in areas involving pharmaceuticals. Although most literature dealing with ILs is still majorly devoted to hydrophobic ILs, evidence on the potential of hydrophilic ILs have been increasingly provided in the past decade, viz., ILs with improved therapeutic efficiency and bioavailability, ILs with the ability to increase drugs' aqueous solubility, ILs with enhanced extraction performance for pharmaceuticals when employed in biphasic systems and other techniques, and ILs displaying low eco/cyto/toxicity and beneficial biological activities. Given their relevance, it is here overviewed the applications of hydrophilic ILs in fields involving pharmaceuticals, particularly focusing on achievements and advances witnessed during the last decade. The application of hydrophilic ILs within fields involving pharmaceuticals is here critically discussed according to four categories: (i) to improve pharmaceuticals solubility, envisioning improved bioavailability; (ii) as IL-based drug delivery systems; (iii) as pretreatment techniques to improve analytical methods performance dealing with pharmaceuticals, and (iv) in the recovery and purification of pharmaceuticals using IL-based systems. Key factors in the selection of appropriate ILs are identified. Insights and perspectives to bring renewed and effective solutions involving ILs able to compete with current commercial technologies are finally provided.

Affinity Tags for Protein Purification

2020 ◽  
Vol 21 (8) ◽  
pp. 821-830
Author(s):  
Vibhor Mishra
Keyword(s):  
Protein Purification ◽  
Protein Complexes ◽  
Affinity Purification ◽  
Protein Domain ◽  
Affinity Tag ◽  
Small Peptides ◽  
Affinity Tags ◽  
C Terminus ◽  
Solubility Enhancers ◽  
As Solubility

The affinity tags are unique proteins/peptides that are attached at the N- or C-terminus of the recombinant proteins. These tags help in protein purification. Additionally, some affinity tags also serve a dual purpose as solubility enhancers for challenging protein targets. By applying a combinatorial approach, carefully chosen affinity tags designed in tandem have proven to be very successful in the purification of single proteins or multi-protein complexes. In this mini-review, the key features of the most commonly used affinity tags are discussed. The affinity tags have been classified into two significant categories, epitope tags, and protein/domain tags. The epitope tags are generally small peptides with high affinity towards a chromatography resin. The protein/domain tags often perform double duty as solubility enhancers as well as aid in affinity purification. Finally, protease-based affinity tag removal strategies after purification are discussed.

Synthesis, Characterization and Applications of Dicationic Ionic Liquids in Organic Synthesis

2020 ◽  
Vol 17 (4) ◽  
pp. 450-464
Author(s):  
Mohammad Javaherian ◽  
Seyyed Jafar Saghanezhad
Keyword(s):  
Ionic Liquids ◽  
Organic Synthesis ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Dicationic Ionic Liquids ◽  
Physical And Chemical ◽  
Reaction Media ◽  
And Chemical Properties

Dicationic ionic liquids are an emerging group of Ionic Liquids (ILs) that are currently receiving much attention as green reaction media and catalysts. Because of a great number of possible combinations of cations and anions, the physical and chemical properties of dicationic ionic liquids are more tunable and broader than monocationic ILs. Therefore, their unique properties have made them the target of many applied and fundamental researches. Actually, dicationic ionic liquids are more effective and rather fascinating than traditional monocationic ILs. So, due to greater versatility and diversity, their applications in organic synthesis have been extensively grown. In this review, we have focused on the synthesis, characterization and applications of dicationic ionic liquids, especially, in organic synthesis.

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