Maria Quental

• Master of Biochemistry
• PhD Student at University of Aveiro

Herein we demonstrate the formation of new stimuli‐responsive aqueous biphasic systems (ABS), able to respond simultaneously to temperature and pH, or just to one stimulus, therefore allowing the design of more sustainable separation processes. This dual behavior is achieved with ABS formed by mono‐ or dicationic protic ionic liquids as phase‐formi...

The purification of value-added compounds by three-phase partitioning (TPP) is a promising alternative to conventional processes since the target compound can be easily recovered from the liquid-liquid interphase. Although this technique has been successfully applied to the recovery of proteins, the minimization of the use of salts and solvents mus...

Despite the progress achieved by aqueous biphasic systems (ABSs) comprising ionic liquids (ILs) in extracting valuable proteins, the quest for bio-based and protein-friendly ILs continues. To address this need, this work uses natural organic acids as precursors in the synthesis of four ILs, namely tetrabutylammonium formate ([N4444][HCOO]), tetrabu...

Ionic-liquid-based aqueous biphasic systems (IL-based ABS) have been described as promising platforms for the extraction and separation of proteins. However, imidazolium-based ILs have been the preferred choice, which may raise some biocompatibility and biodegradability concerns. In this work, novel ABS composed of tetraalkylammonium-based ILs and...

The ubiquitous instability of RNA along with issues associated to its purity degree have been preventing its widespread use as low-cost biotherapeutics. Based on the well-known capacity of amino acids to specifically interact with RNA when used as chromatographic ligands, a set of amino-acid-based ionic liquids (AA-ILs) was herein investigated, bot...

RNA is a biopolymer of high relevance in the biopharmaceuticals field and in fundamental and applied research; however, preservation of RNA stability is still a remarkable challenge. Herein, we demonstrate the enhanced potential of aqueous solutions of self-buffering cholinium-based Good's buffers ionic liquids (GB-ILs), at 20 and 50% (w/w), as alt...

Aiming at designing effective and sustainable separation processes, herein we propose the use of carbohydrates combined with tetralkylphosphonium- and tetralkylammonium-based ionic liquids (ILs) to form aqueous biphasic systems (ABS). The formation of ABS composed of non-aromatic and non-fluorinated ILs with carbohydrates is here shown for the firs...

In the past decade it has been demonstrated the remarkable potential of ionic-liquid-based aqueous biphasic systems (IL-based ABS) to extract and purify a large range of valued-added biocompounds. However, the transposal of lab-experiments to an industrial scale has been precluded by a poor understanding of the molecular-level mechanisms ruling the...

BACKGROUND The use of antibodies, such as immunoglobulin G (IgG), has seen a significant growth in recent decades for biomedical and research purposes. However, antibodies are high cost biopharmaceuticals, for which the development of alternative and cost‐effective purification strategies is still in high demand. RESULTS Aqueous biphasic systems (...

Based on the particular ability of aliphatic amino acids to form aqueous biphasic systems with ionic liquids, it is here shown how these systems can be used to selectively and efficiently separate mixtures of aliphatic and aromatic amino acids usually present in protein hydrolysates or fermentation broths.

Ionic liquids (ILs) have been proposed as promising media for the extraction and separation of bioactive compounds from the most diverse origins. This critical review offers a compilation on the main results achieved by the use of ionic-liquid-based processes in the extraction and separation/purification of a large range of bioactive compounds (inc...

BACKGROUND - Self-buffered aqueous biphasic systems (ABS) are prepared with ionic liquids (ILs) based in Good's buffers (GB-ILs) and used to purify proteins. RESULTS - A set of new GB-ILs based on the tetrabutylphosphonium cation ([P4444]+) was here synthesized and characterized. The self-buffering behaviour of the GB-ILs was asserted by measuring...

In the past decade, remarkable advances on the production and use of antibodies as therapeutic drugs and in research/diagnostic purposes have lead to their recognition as value-added proteins. These biopharmaceuticals have become increasingly important, reinforcing the current demand on the development of more benign, scalable and cost-effective te...

In order to overcome the lack of characterization on the relative hydrophobicity of aqueous biphasic systems (ABS), the partition of three alkaloids as alternative probes, was evaluated in a series of biocompatible ABS composed of cholinium-based salts or ionic liquids (ILs) and polyethylene glycol (PEG). The caffeine partitioning in ABS was firstl...

Ionic-liquid-based aqueous biphasic systems (IL-based ABS) have been largely investigated as promising extraction and purification routes. In this context, the determination of their phase diagrams and the physical properties of the coexisting phases are of high relevance when envisaging their large-scale applications. Low viscosities improve mass...

Aqueous biphasic systems (ABS) composed of ionic liquids (ILs) are promising platforms for the extraction and purification of proteins. In this work, a series of alternative and biocompatible ABS composed of cholinium-based ILs and polypropylene glycol were investigated. The respective ternary phase diagrams, tie-lines, tie-line lengths and critica...

Good's buffers ionic liquids (GB-ILs), composed of cholinium-based cations and Good's buffers anions, display self-buffering characteristics in the biological pH range, and their polarity and hydrophobicity can be easily tuned by a proper manipulation of their ions chemical structures. In this work, the extraction ability for bovine serum albumin (...

Although previous works attempted to characterize the liquid-liquid phase behaviour between water and ionic liquids (ILs), the impact of non-cyclic cations in these solubilities is poorly studied and yet to be understood. In this work, the mutual solubilities between water and ILs containing the anion bis(trifluoromethylsulfonyl)imide, [NTf2]-, com...

This work reports a promising approach on the development of novel self-buffering and biocompatible ionic liquids for biological research in which the anions are derived from biological buffers (Good's buffers, GB). Five Good's buffers (Tricine, TES, CHES, HEPES, and MES) were neutralized with four suitable hydroxide bases (1-ethyl-3-methylimidazol...