Antonio J. Galera-Carrillo, Elizabeth Torres-Párraga, Antonio Franconetti, Francisca Cabrera-Ecribano

Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, C/Profesor García González 1, 41012 Sevilla, España

Contact email: agalera@us.es

Chitosan is a biodegradable, biocompatible and non-toxic natural polymer derived from chitin. It presents a structure that provides with a wide number of features which could be interesting for its applicability in different fields. On the other hand, polyphenolic compounds, such as hydroxytyrosol, have shown a marked anti-inflammatory and antioxidant properties directly related to cardiovascular diseases, neurodegeneration, metabolic syndrome or cancer.

Preparation of a serie of chitosan derivates, particulary polyphenolic systems, will be described in this work. This purpose will be carried out by taking advantage of the reactivity of chitosan´s amino group. These new compounds consist of quaternized salts with structure of pyrylium or quinolinium salts depending on they were synthesized by reaction of chitosan with polyphenolic pyrylium salts or polyhydroxysubstituted 3-desoxyanthocianines salts respectively . Pyrylium and anthocyanin salts used to obtain such systems were previously synthesized by means of a methodology optimized by this group. It consists of using ortho, meta and/or para-substituted acetophenones as well as ortho, meta and / or para-substituted benzaldehyde in the presence of a Lewis acid, which mediates in the dehydration and cyclation process.

All the new compounds have been characterized by NMR and MS techniques. Finally, in order to study the applicability of these compounds, photophysical properties, antioxidant capacity and glutathione peroxidase mimetics will be studied.

The authors thank the Junta de Andalucía (2011/FQM-142, and Project P09-AGR-4597); Spanish Ministerio de Economía, Industria y Competitividad (MINECO), Spain (CTQ2016-78703-P); A. J. Galera-Carrillo also thanks Universidad de Sevilla (PEJUS-2, 2017-2-EJ-070) for funding support. The authors also thank the CITIUS, Universidad de Sevilla, for the facilities.

Metal−organic frameworks, or MOFs, have emerged as an extensive class of crystalline materials with ultrahigh porosity (up to 90% free volume) and enormous internal surface areas, extending beyond 6000 m²/g. These properties, together with the extraordinary degree of variability for both the organic and inorganic components of their structures, make MOFs of interest for potential applications in clean energy, most significantly as storage media for gases such as hydrogen and methane, and as high-capacity adsorbents to meet various separation needs. Additional applications in membranes, thin film devices, catalysis, and biomedical imaging are increasingly gaining importance. On a fundamental level, MOFs epitomize the beauty of chemical structures and the power of combining organic and inorganic chemistry, two disciplines often regarded as disparate. Since the 1990s, this area of chemistry has experienced an almost unparalleled growth, as evidenced by not only the sheer number of research papers published but also the ever-expanding scope of the research [1].

Among the large family of metal–organic frameworks (MOFs), Zr-based MOFs, which exhibit rich structure types, outstanding stability, intriguing properties and functions, are foreseen as one of the most promising MOF materials for practical applications. Although this specific type of MOF is still in its early stage of development, significant progress has been made in recent years. Herein, advances in Zr-MOFs since 2008 are summarized and reviewed from three aspects: design and synthesis, structure, and applications. Four synthesis strategies implemented in building and/or modifying Zr-MOFs as well as their scale-up preparation under green and industrially feasible conditions are illustrated first. Zr-MOFs with various structural types are then classified and discussed in terms of different Zr-based secondary building units and organic ligands. Finally, applications of Zr-MOFs in catalysis, molecule adsorption and separation, drug delivery, and fluorescence sensing, and as porous carriers are highlighted [2].

In this research, ZrCl₄ and 1,4-benzene-dicarboxylic acid) H₂BDC( were mixed in a very few drops of DMF (Dimethylformamide) by mechanochemical method. The characterization of the obtained metal-organic framework was conducted by XRD, FTIR, SEM.

Micellar extraction method (MME - Micellar Mediated Extraction) is an alternative method of classical extraction, which takes place with the participation of surfactants. In this method, instead of an organic solvent, a highly efficient solution of surfactants is used, which dissolves the desired component in hydrophobic micelles. Micellar extraction is often used for separating analytes from complex matrices, enriching analytes in environmental research, as well as for determining trace amounts of heavy metals or toxins in biological samples.

Main goal of presented study was to compare conventional extraction (using ethanol solutions) with micellar extraction (carried out with Whey Protein Isolated - WPI solutions and Whey Protein Concentrated - WPC). The test material consisted of dried elderberry (Sambucus nigra) fruits. The comparison of the obtained extracts was performed by analyzing the content of reducing compounds, the flavonoid content and the ability to reduce iron (III) ions in a system of three variables: temperature, concentration and time.

The obtained results clearly shows that, the factor influencing the efficiency of micellar extraction using WPC and WPI was time. The catechin content in the studied WPC extracts from WPI. The higher ability to reduce iron (III) ions was characterized by WPC protein extract as opposed to WPI extracts. The content of flavonoids in micellar extraction using protein extracts from WPC was higher than with the use of protein extracts from WPI.

The work reports Ultrasound assisted diethyl (2-(1-(morpholinomethyl)-2-oxoindolin-3-ylidene)hydrazinyl) (substituted phenyl/heteryl) methylphosphonate 9(a-j) derivatives. The derivatives are synthesized using green protocol. In the first step 3-hydrazonoindolin-2-one is synthesized using ultrasound. In the second step diethyl (substituted phenyl/heteryl)(2-(2-oxoindolin-3-ylidene)hydrazinyl) methylphosphonate 6(a-j) derivatives using cerric ammonium nitrate as catalyst. In the third step diethyl (2-(1-(morpholinomethyl)-2-oxoindolin-3-ylidene)hydrazinyl) (substituted phenyl/heteryl) methylphosphonate 9(a-j) derivatives are synthesized using ultrasound. Isatin, chemically known as H-indole-2,3-dione, and its derivatives possess a broad range of biological and pharmacological properties. Isatin is widely used as starting material for the synthesis of a broad range of heterocyclic compounds and as substrates for drug synthesis. The α-amino phosphonate derivatives constitute an important class of organophosphorus compounds on account of their versatile biological activity. morpholine moiety has been found to be of an eminent pharmacophore in medicinal chemistry. A number of molecules possessing morpholine moiety are clinically approved drugs. The importance of this ring is well understood by medicinal chemists, since they play a major role in molecular properties such as an electronic distribution, three dimensionality, scaffold flexibility/rigidity, lipophilicity or polarity and metabolic stability. Considering the importance of the three pharmacophores, promoted us to club these pharmacophores together in a single molecule using green synthetic protocol. The structures of the ultrasound synthesized compounds were confirmed by spectral analysis like IR, ¹H NMR, ¹³C NMR, ³¹P NMR and MS.

Since the effect of environmental water on certain properties of Ionic Liquids (ILs) can be decisive when considering a possible industrial application, the effect of environmental water absorption on electrical conductivity (using a conductimeter Crison Basic 30) and viscosity (using a rheometer AR2000 TA Instruments) of two diethylmethylammonium ionic liquids was analyzed. The studied compounds are based on a cation (diethylmethylammonium) and two anions (methanesulfonate and trifluoromethanesulfonate).

In both ionic liquids the water absorption corresponded to a fickian behavior, agreeing with previous literature data of other ILs [1], being the methanesulfonate much more hygroscopic than the trifluoromethanesulfonate (28% and 6% in weight for [C₂C₂C₁N][MeSO₃] and [C₂C₂C₁N][OTf], respectively). As it was expected, water considerably increases the ionic conductivity; values were duplicated in case of [C₂C₂C₁N][OTf] and quadruplicated for [C₂C₂C₁N][MeSO₃]. Likewise, the viscosity decreases drastically with water incorporation in the IL; changes of 88 % and 66% for trifluoromethanesulfonate and methanesulfonate, respectively, were measured.

Furthermore, in the case of diethylmethylammonium trifluoromethanesulfonate, the functional dependence of the viscosity with the molar fraction of water was studied. According to the observed behavior, the viscosity of the pure IL was estimated using the equation proposed by Seddon et al. [2].

Density, speed of sound, and derived magnitudes of two diethylmethylammonium ILs against temperature have been studied in this work. The chosen ILs were diethylmethylammonium trifluoromethanesulfonate, [C₂C₂C₁N][OTf], and diethylmethylammonium methanesulfonate [C₂C₂C₁N][MeSO₃]. In order to analyse the influence of water content, saturated and dried samples of these ILs were studied. ILs were dried using a vacuum pump, and the saturation level (28% and 6% in weight for [C₂C₂C₁N][MeSO₃] and [C₂C₂C₁N][OTf], respectively) was achieved by keeping the ILs in an open bottle at ambient temperature. Direct measurements of density and speed of sound were taken with an Anton Paar DSA 5000. Linear equations were used to express the correlation with temperature of both properties and the thermal expansion coefficient, and the adiabatic bulk modulus constant have been obtained using expressions proposed in the bibliography [1-3].

The effect of water content is different on both properties. Thus, the density of the samples slightly increases when water is removed whereas opposite behaviour was found with regard to the speed of sound, which decreases when the water content was completely removed.

The ecotoxicity of a nitrate-based Ionic Liquid (IL) and saturated mixtures with four nitrate salts was tested in this work, towards the bioluminescent bacteria Vibrio fischeri, using the Microtox^® standard toxicity test [1]. The selected IL was Ethylammonium Nitrate (EAN) and the nitrate salts were Lithium Nitrate (LiNO₃), Calcium Nitrate (Ca(NO₃)₂), Magnesium Nitrate (Mg(NO₃)₂) and Aluminum Nitrate (Al(NO₃)₃). The effective concentration (EC₅₀) of these mixtures was determined over three standard periods of time, namely 5, 15 and 30 min [2].

Results of EC₅₀ for pure EAN at 15 minutes are in relatively good concordance with Montalbán et al. [3]. To the best of our knowledge, no ecotoxicity studies have been performed for doped EAN.

Similar results have been found for pure EAN and for EAN doped with LiNO₃ and Mg(NO₃)₂, whose values indicated low toxicity. Nevertheless the addition of Ca(NO₃)₂ and Al(NO₃)₃ cause an increase on the ecotoxicity of EAN, specially for the IL doped with Al(NO₃)₃ which present values associated to highly toxic compounds, even comparable with benzene or atrazine [2].

The reaction of furfural with secondary amines and isopropyl cyanoacetate leads to the formation of the previously unknown diisopropyl 8-(dialkylamino)-2,4-dicyano-3-(2-furyl)-6-oxobicyclo[3.2.1]octane-2,4-dicarboxylates. The tructure of the products was confirmed by NMR and X-ray analysis.

The work reports synthesis of ten novel derivatives of 5-(1-(substituted phenyl)-4,5-diphenyl-1H-imidazol-2-yl)-4-methylthiazole 5(a-o). The reaction of benzil, primary aryl amines, 4-methylthiazole-5-carbaldehyde, and ammonium acetate was carried out in one pot in presence of eco-friendly catalyst cerric ammonium nitrate in solvent ethanol to give final compounds. The synthesized derivatives were evaluated for their in vitro antifungal activity against pathogenic fungal stains. Molecular modelling studies suggested that some of the synthesized derivatives, especially 5b and 5c exhibited excellent antifungal activity whereas all imidazole derivatives 5(a-o) have potential to explore in the drug discovery pipeline for antifungal agents. The structures of the synthesized compounds were confirmed by spectral characterization such as IR, ¹H NMR, ¹³CNMR and Mass spectral studies. In addition to this the in silico ADMET study, was also performed which proves that the synthesized compounds exhibit good oral absorption and are non- toxic in nature.

Solvent-catalyst free synthesis of poly-heterocycles containing imidazo[1,2-a]pyridine and Tetrazolo[1,5-a]quinoline frameworks via a one-pot process: IMCR Groebke-Blackburn-Bienaymé reaction (GBBR)/S_NAr/ ring-chain azido tautomerization under ecofriendly conditions. The Tetrazolo[1,5-a]quinoline and imidazo [1,2-a] pyridine scaffolds are the structural core of various compounds with interesting pharmacological properties and could lead to the discovery of novel bioactive molecules.