In this study, the hydrothermal upgrading (HTU) of high sulfur-content heavy oil was investigated at sub-critical (Sub-CW), near-critical (NCW) and supercritical water (SCW) conditions. Products obtained after HTU, including gases, liquid, and coke (if formed), were analyzed to understand the upgrading performance at different conditions. At Sub-CW (200, 250, and 300 °C), 250 °C is the optimum temperature where a viscosity reduction from 2073 to 1758 mPa s was achieved with a slight removal of sulfur (mainly sulfur) and the generation of a small amount of light and non-condensable hydrocarbons in gas phase (C1–C4, isoalkanes and alkenes, H2S, CO2 and H2, etc.). At NCW (350 °C) and SCW (400 °C), heavy oil was upgraded into light oil with a significant removal of heteroatoms, an increase of saturates content, a reduction of aromatics, resins and asphaltenes contents, and a high yield of light gaseous hydrocarbons (mainly methane). Simultaneously, each SARA fraction was also greatly ameliorated: the content of light alkanes with low molecular weight in saturates was increased, diaromatics content in aromatics was increased with a reduction of polyaromatics content, aromatics-type carbon atoms in resins was increased with a decrease in aliphatic hydrocarbons. Moreover, MALDI-TOF measurements of asphaltenes show that the molecular weights of asphaltenes were reduced. All these results indicated that HTU at Sub-CW can be used for heavy oil pre-treatment (in-situ or ex-situ upgrading) considering its main effect of viscosity reduction with a small removal of heteroatoms, while HTU at NCW and SWC has a great potential in in-situ and ex-situ upgrading and oil refining as it can convert heavy oil into light oil. © 2019 Elsevier B.V.

The ubiquitous occurrence of perfluoroalkyl substances (PFAS) in the open ocean has been previously documented, but their vertical transport and oceanic sinks have not been comprehensively characterized and quantified at the oceanic scale. During the Malaspina 2010 circumnavigation expedition, 21 PFAS were measured at the surface and at the deep chlorophyll maximum (DCM) in the Atlantic, Indian and Pacific oceans. In this work, we report an extended data set of PFAS dissolved phase concentrations at the DCM. ∑PFAS at the DCM varied from 130 to 11000 pg L-1, with a global average value of 500 pg L-1. Perfluorooctanesulfonate (PFOS) abundance contributed 39\% of ∑PFAS, followed by perfluorodecanoate (PFDA, 17\%), and perfluorohexanoate (PFHxA, 12\%). The relative contribution of the remaining compounds was below 10\%, with perfluorooctanoate (PFOA) contributing only 5\% to PFAS measured at the DCM. Estimates of vertical diffusivity, derived from microstructure turbulence observations in the upper (<300 m) water column, allowed the derivation of PFAS eddy diffusive fluxes from concurrent field measurements of eddy diffusivity and PFAS concentrations. The PFAS concentrations at the DCM predicted from an eddy diffusivity model were lower than field-measured concentrations, suggesting a relevant role of other vertical transport mechanisms. Settling fluxes of organic matter bound PFAS (biological pump), oceanic circulation and potential, yet un-reported, biological transformations are discussed. © 2019 The Royal Society of Chemistry.

Overuse and misuse of antibacterial drugs has resulted in bacteria resistance and in an increase in mortality rates due to bacterial infections. Therefore, there is an imperative necessity of new antibacterial drugs. Bio-organometallic derivatives of antibacterial agents offer an opportunity to discover new active antibacterial drugs. These compounds are well-characterized products and, in several examples, their antibacterial activities have been studied. Both inhibition of the antibacterial activity and strong increase in the antibiotic activity of the parent drug have been found. The synthesis of the main classes of bio-organometallic derivatives of these drugs, as well as examples of the use of structure–activity relation (SAR) studies to increase the activity and to understand the mode of action of bio-organometallic antimicrobial peptides (BOAMPs) and platensimicyn bio-organometallic mimics is presented in this article. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

In this work six diversely substituted N-propargylated-1,3,5-triazines have been designed, synthesized, and evaluated as monoamine oxidase (MAO) inhibitors. Very surprisingly, only 4,6-dichloro-N-(prop-2-yn-1-yl)-1,3,5-triazin-2-amine (1) showed modest, but selective MAO−B inhibition (IC50=14.2 ± 0.7 μM), whose binding affinity has been investigated by computational analysis. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

We report on optical studies of a boron-dipyrromethene (BODIPY) based conjugated microporous polymer, CMPBDP, a promising material for application in photonic devices, and those of two related model dyes (MD1 and MD2). We used time-resolved fluorescence spectroscopy and theoretical calculations to elucidate the photobehavior of the three material systems. Because of their extended π-conjugation framework, the more intense band in the absorption spectra shows a large bathochromic shift (1581, 1969 and 1158 cm-1, respectively) when compared to that of the unsubstituted BODIPY. Furthermore, the Stokes shift of the main emission bands of MD1 and MD2 depends on the solvent polarity. Both absorption and emission bands of MD2 and CMPBDP suggest the presence of two different species in the S0 and S1 states. The time-resolved fluorescence results show that the initially populated S1 state gives rise to intramolecular charge transfer (ICT) and twisted intramolecular charge transfer (TICT) states within ∼0.3 ps and 2-13 ps, respectively. The ICT structures decay in 0.1-1 ns, while the TICT structures decay in 3-5 ns. The theoretical calculations suggest that for MD1 the electron charge density shifts from the ethynylbenzene moiety to the BODIPY core, while for MD2 it moves in the opposite direction. Our findings depict the complex photodynamics of these BODIPY-based dyes and polymer. They could be used in the design of other molecular systems having the same family members as the central chromophore for photonic applications. © 2019 The Royal Society of Chemistry.

The controlled preparation of two types of α-seleno-α,β-unsaturated carbonyls, namely, α-selenoenals and α-selenoenones, has been accomplished directly from allenes through metal-free oxidative selenofunctionalization reactions. The decisive role of organoselenium and 1-fluoropyridinium reagents has been disclosed. The divergent reactivity due to the presence or absence of an ethoxycarbonyl moiety at the allene end has also been studied. A tentative pathway implying selective electrophilic addition of the selenium reagent to the allene moiety followed by adventitious water attack and concomitant oxidation has been proposed. © the Partner Organisations 2019.

Matrix solid-phase dispersion (MSPD) is a nowadays widely accepted technique for the one-step extraction and purification of organic analytes in different research areas. The several innovations incorporated since its introduction 30 years ago have progressively contributed to increase its simplicity, flexibility, rapidity, robustness and straightforward nature. In recent years, progress in MSPD has continued through the incorporation of new engineered and tailored sorbents and solvents to the process, which have facilitated its miniaturization due to the enhanced sorption capacities and improved selectivity provided by these reagents. In some cases, these improved features have also stimulated the combined use of MSPD with other enhanced solvent extraction techniques, resulting in even faster, greener and less manipulative methodologies. This review paper discusses recent advances in these fields through representative application studies dealing with the analysis of organic compounds in environmental and food samples. © 2019 Elsevier B.V.

The last decade has witnessed a renewed interest in selenium (Se) as an element able to prevent a range of illnesses in humans, mainly through supplementation. However, such supplementation relies on species such as sodium selenite or selenomethionine, which proved to have limited solubility and bioavailability, thus leading to limited activity. To overcome this limitation, other selenium species need to be explored, such as phthalic selenoanhydride (R-Se), which is soluble in physiological media. R-Se releases various reactive selenium species (RSeS), including hydrogen selenide (H2Se), that can interact with cellular components, such as glutathione (GSH) and hydrogen sulfide (H2S). This interplay between R-Se and the cellular components provides a sophisticated biochemical release mechanism that could be behind the noteworthy biological activities observed for this compound. In order to investigate the interactions of phthalic chalcogen anhydrides with H2S or GSH, we have employed UV-vis spectrophotometry, electron paramagnetic resonance spectroscopy (EPR) and plasmid DNA (pDNA) cleavage assay. We found that apart from R-Se, the other analogues do not have the ability to scavenge the cPTIO radical or to cleave pDNA on their own. In contrast, the scavenging potency for the cPTIO radical and for the O2- radical exerted by R-Se and its sulfur analogue (R-S) significantly increased when they were evaluated in the presence of H2S. However, GSH only changed the radical scavenging activity of R-Se. These new discoveries may explain some of the biological activities associated with this class of compounds and open a new approach to ascertain the possible mechanisms underlying their biological actions. © 2019 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.

We describe a general and practical strategy for the direct one-step incorporation of a tunable solubility module at the boron atom of F-BODIPY dyes. The tethering reaction uses easy-to-handle reagents, has broad functional group compatibility and proceeds under mild conditions without requiring any pre-functionalization of the starting F-BODIPY to yield the solubility-tagged O-BODIPY derivative in 51–86\% yield. The module can be introduced at the end of the synthetic route without perturbing the fluorophore scaffold, thus minimizing difficulties in product isolation. Its orthogonal geometrical arrangement with respect to the plane of the BODIPY chromophore hampers intermolecular aggregation processes that quench fluorescence, while the covalent attachment to the boron atom has a minimal effect on the absorption properties. Fully water-soluble and hydrolytically stable BODIPYs were prepared by incorporating either neutral (tetra- and octaethylene glycol chains) or zwitterionic (sulfobetaine) hydrophilic tags in the module. The new dyes are valuable live cell imaging probes that ameliorate the undesired partitioning into lipophilic compartments that is often observed for standard BODIPYs. This strategy can be readily adapted to the general and highly practical post-synthetic introduction of new functionalities into F-BODIPY dyes, including phase-tagging, by appropriately choosing the nature of the chemical tags attached to the module. © 2019 Elsevier Ltd

Chondroitin sulfates are linear anionic sulfated polysaccharides found in biological tissues, mainly within the extracellular matrix, which are degraded and altered by specific lyases depending on specific time points. These polysaccharides have recently acquired relevance in the pharmaceutical industry due to their interesting therapeutic applications. As a consequence, chondroitin sulfate (CS) lyases have been widely investigated as tools for the development of new pharmaceuticals based on these polysaccharides. This review focuses on the major breakthrough represented by chondroitin sulfate-degrading enzymes and their structures and mechanisms of function in addition to their major applications. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.

Tacrine was the first drug to be approved for Alzheimer’s disease (AD) treatment, acting as a cholinesterase inhibitor. The neuropathological hallmarks of AD are amyloid-rich senile plaques, neurofibrillary tangles, and neuronal degeneration. The portfolio of currently approved drugs for AD includes acetylcholinesterase inhibitors (AChEIs) and N-methyl-d-aspartate (NMDA) receptor antagonist. Squaric acid is a versatile structural scaffold capable to be easily transformed into amide-bearing compounds that feature both hydrogen bond donor and acceptor groups with the possibility to create multiple interactions with complementary sites. Considering the relatively simple synthesis approach and other interesting properties (rigidity, aromatic character, H-bond formation) of squaramide motif, we combined this scaffold with different tacrine-based derivatives. In this study, we developed 21 novel dimers amalgamating squaric acid with either tacrine, 6-chlorotacrine or 7-methoxytacrine representing various AChEIs. All new derivatives were evaluated for their anti-cholinesterase activities, cytotoxicity using HepG2 cell line and screened to predict their ability to cross the blood-brain barrier. In this contribution, we also report in silico studies of the most potent AChE and BChE inhibitors in the active site of these enzymes. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.

While testing the ability of cyclodextrin glucanotransferases (CGTases) to glucosylate a series of flavonoids in the presence of organic cosolvents, we found out that this enzyme was able to glycosylate a tertiary alcohol (tert-butyl alcohol). In particular, CGTases from Thermoanaerobacter sp. and Thermoanaerobacterium thermosulfurigenes EM1 gave rise to the appearance of at least two glycosylation products, which were characterized by mass spectrometry (MS) and nuclear magnetic resonance (NMR) as tert-butyl-α-D-glucoside (major product) and tert-butyl-α-D-maltoside (minor product). Using partially hydrolyzed starch as glucose donor, the yield of transglucosylation was approximately 44\% (13 g/L of tert-butyl-α-D-glucoside and 4 g/L of tert-butyl-α-D-maltoside). The synthesized tert-butyl-α-D-glucoside exhibited the typical surfactant behavior (critical micellar concentration, 4.0–4.5 mM) and its properties compared well with those of the related octyl-α-D-glucoside. To the best of our knowledge, this is the first description of an enzymatic α-glucosylation of a tertiary alcohol. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.

Chamaemelum fuscatum (Brot.) Vasc. is a south west Iberian chamomile that has been traditionally used as folk medicine in its natural distribution area but currently it is underestimated regarding its biological activities. For this reason, it is proposed in this paper to get insight into the scientific validation of the traditional knowledge of this plant with the aim of taking advantage of its anti-inflammatory, gastroprotective and antinociceptive activities, among others. To this aim, the chemical composition of the essential oil from the whole plant, the flowers and the green parts of this plant has been evaluated by gas chromatography-mass spectrometry (GC-MS). Plant materials were collected in Badajoz (Spain). A total of 61 components including monoterpenoids, sesquiterpenoids and aliphatic esters were identified. (E)-2-Methyl-2-butenyl methacrylate (27.57\%-18.53\%) and 2-methylallyl isobutyrate (9.79\%-7.51\%) were the most abundant compounds in the essential oils of flowers and of the whole plant, whereas α-curcumene, trans-pinocarveol, α-bergamotene and pinocarvone were the major terpenoids irrespective of the plant part considered. Certain compounds showing a relative high abundance as isobutyl methacrylate, isoamyl butyrate, α-bergamotene and pinocarvone were identified for the first time in this species. Finally, we have reviewed the bioactivity of several compounds to relate the ethnobotanical use of this plant in Spain with its volatile profile. This work is a preliminary contribution to reinforce the use to this Mediterranean endemic plant as a natural source of bioactives. © 2019 by the authors.