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Wine comprises a beloved food and human companion since the early times of humans on earth. In this study, wine samples of different type (red, white, and rose) and variety (Agiorgitiko, Augoustiatis, Cabernet Sauvignon, Syrah, Vlahiko, Assyrtiko, Chardonnay, Debina, Moschofilero, Vidiano, Syrah plus Mandilari, and Xinomavro) were subjected to physico-chemical and aroma compounds analyses, in an effort to characterize their identity and discriminate these samples according to variety using statistics. Results showed significant differences (p

The synthesis of heteroleptic monomeric cationic Rh(I) bis-diphosphine complex [Rh(dppe)(dppp)]Cl (dppe = 1,2-bis-(diphenylphosphino)ethane and dppp = 1,3-bis-(diphenylphosphino)propane) was achieved by reaction between the neutral dimeric complex [Rh2(dppe)2(μ2-Cl)2] and the dppp ligand. The corresponding complex [Rh(dppe)(dppp)]BF4 was instead obtained from reaction between [Rh(dppe)(nbd)]BF4 (nbd = bicyclo-[2.2.1]-hepta-2,5-diene) and the dppp ligand. Previous protocols had extended to the synthesis of the analogous homoleptic complexes containing two dppe or two dppp ligands. The structural analysis of such complexes conducted in the solid state by single-crystal x-ray crystallography and in solution by 31P and 1H NMR revealed a distorted square planar geometry where the anion and the cation are not bonded each other. Nevertheless, important differences in reactivity can be found if same complexes with different anions are compared, as in the case of the phosphine exchange reaction between [Rh(dppp)2]X (X = Cl−, BF4−) and the dppe ligand or in the case of the employment of such complexes as catalytic precursors for the transfer hydrogenation reaction from 2-propanol to acetophenone.

The production of saffron spice generates large quantities of plant by-products: over 90% of the plant material collected is discarded, and a consideration fraction of this waste is plant stamens. This work investigated the chemical composition and the antimicrobial activities of the non-polar fraction extracted from four different saffron flower stamens. The chemical composition of ethereal extracts of the saffron stamens was qualitatively assessed by means of gas–chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) analyses. These analyses revealed ethereal extracts to possess a high polyunsaturated fatty acid content. In vitro antibacterial activity of stamen extracts showed no large differences between Gram-positive and Gram-negative bacteria in terms of minimal inhibitory concentration (MIC). In food matrix microbial analysis of the bacterial strains belonging to the main foodborne pathogen species, including Staphylococcus aureus DSM 20231, Escherichia coli DSM 30083, and Listeria monocytogenes DSM 20600, using low-fat UHT milk, revealed a statistically significant reduction in the number of cells (particularly for E. coli and S. aureus with a complete elimination of the population of the two target bacteria following incubation in diethyl ether extracts of saffron stamen (DES) at high concentrations tested, both at 37 °C and 6 °C (for 48 h and 7 days, respectively). A synergic effect was observed when the pathogens were incubated at 6 °C with DES. This work shows these by-products to be excellent sources of bioactive compounds, which could be exploited in high-added-value products, such as food, cosmetics, and drugs.

Three ternary mixtures composed by choline chloride (ChCl), ethylene glycol (EG), and a second hydrogen bond donor (HBD) as ethanol (A), 2-propanol (B), and glycerol (C) were studied in terms of composition related to the band gap energy (BGE). A Design of Experiments (DoE) approach, and in particular a Simple Lattice three-components design, was employed for determining the variation of the BGE upon the composition of each system. UV-VIS analysis and subsequent Tauc plot methodology provided the data requested from the DoE, and multivariate statistical analysis revealed a drop of the BGE in correspondence to specific binary compositions for systems A and B. In particular, a BGE of 3.85 eV was registered for the mixtures ChCl/EtOH (1:1) and ChCl/2-propanol (1:1), which represents one of the lowest values ever observed for these systems.

The selective formation of the heterocyclic salt ((1,4-dioxane-2,5-diyl)-bis-(methylene))-bis-(triphenylphosphonium) chloride was observed when epichlorohydrin and triphenylphosphine were reacted in CH2Cl2 at room temperature. Slow evaporation from a mixture of ethanol and ethyl acetate allows to isolate monocrystals of the heterocyclic phosphonium salt. Mechanistic investigations point to the formation of the zwitterionic intermediate 1-chloro-3-(triphenylphosphonio)-propan-2-olate, which can dimerize and generate the 1,4-dioxane derivative. In the exclusive presence of a Brønsted acid as HCl, which usually facilitates epoxide ring opening, the exclusive formation of 1,3-dichloro-2-propanol was although observed. Also, when epichlorohydrin, PPh3, and a stoichiometric amount of HCl were mixed, (2-chloro-3-hydroxypropyl)-triphenylphosphonium chloride was formed and its isolation in pure form provides monocrystals subjectable to X-ray analysis.

Deep Eutectic Systems (DESs) are obtained by combining Hydrogen Bond Acceptors (HBAs) and Hydrogen Bond Donors (HBDs) in specific molar ratios. Since their first appearance in the literature in 2003, they have shown a wide range of applications, ranging from the selective extraction of biomass or metals to medicine, as well as from pollution control systems to catalytic active solvents and co-solvents. The very peculiar physical properties of DESs, such as the elevated density and viscosity, reduced conductivity, improved solvent ability and a peculiar optical behavior, can be exploited for engineering modular systems which cannot be obtained with other non-eutectic mixtures. In the present review, selected DESs research fields, as their use in materials synthesis, as solvents for volatile organic compounds, as ingredients in pharmaceutical formulations and as active solvents and cosolvents in organic synthesis, are reported and discussed in terms of application and future perspectives.

The employment of easily affordable ruthenium(II)-complexes as pre-catalysts in the transfer hydrogenation of carbonyl compounds in deep eutectic media is described for the first time. The eutectic mixture tetrabutylammonium bromide/formic acid = 1/1 (TBABr/HCOOH = 1/1) acts both as reaction medium and hydrogen source. The addition of a base is required for the process to occur. An extensive optimization of the reaction conditions has been carried out, in terms of catalyst loading, type of complexes, H2-donors, reaction temperature and time. The combination of the dimeric complex [RuCl(p-cymene)-μ-Cl]2 (0.01–0.05 eq.) and the ligand dppf (1,1′-ferrocenediyl-bis(diphenylphosphine)ferrocene) in 1/1 molar ratio has proven to be a suitable catalytic system for the reduction of several and diverse aldehydes and ketones to their corresponding alcohols under mild conditions (40–60 °C) in air, showing from moderate to excellent tolerability towards different functional groups (halogen, cyano, nitro, phenol). The reduction of imine compounds to their corresponding amine derivatives was also studied. In addition, the comparison between the results obtained in TBABr/HCOOH and in organic solvents suggests a non-innocent effect of the DES medium during the process.

Films with different morphology can be obtained by mixing fish gelatin, Tara gum and glycerol in different ratio and by subjecting the Tara gum to a ball milling treatment before its use. The amount of the plasticizer glycerol, as well as the type of Tara gum employed (as received or milled) resulted, from SEM and AFM analyses, to strong influencing the morphology of the films and their density. Also, the morphological differences determine different thermal and mechanical behaviours. In particular, the employment of milled Tara gum allows to improve the thermal stability, as well as the mechanical properties of the polymers. A similar outcome can be obtained by increasing the glycerol content, which can be used up to 20 wt%. Glycerol amounts exceeding that percentage, are detrimental for the quality of the films and reduce their thermal and mechanical performances., FEDER (Fondo Europeo de Desarrollo Regional) and both the Spanish Agencia Estatal de Investigacióon (MAT2017–84501-R; MAT2017-88923-P) and the Consejería de Educación, Junta de Castilla y León (BU306P18)

The unprecedented Nazarov cyclization of a model divinyl ketone using phosphonium-based Deep Eutectic Solvents as sustainable non-innocent reaction media is described. A two-level full factorial Design of Experiments was conducted for elucidating the effect of the components of the eutectic mixture and optimizing the reaction conditions in terms of temperature, time, and substrate concentration. In the presence of the Deep Eutectic Solvent (DES) triphenylmethylphosphonium bromide/ethylene glycol, it was possible to convert more than 80% of the 2,4-dimethyl-1,5-diphenylpenta-1,4-dien-3-one, with a specific conversion, into the cyclopentenone Nazarov derivative of 62% (16 h, 60 &deg, C). For the reactions conducted in the DES triphenylmethylphosphonium bromide/acetic acid, quantitative conversions were obtained with percentages of the Nazarov product above 95% even at 25 &deg, C. Surface Responding Analysis of the optimized data furnished a useful tool to determine the best operating conditions leading to quantitative conversion of the starting material, with complete suppression of undesired side-reactions, high yields and selectivity. After optimization, it was possible to convert more than 90% of the model substrate into the desired cyclopentenone with cis percentages up to 77%. Experimental validation of the implemented model confirmed the robustness and the suitability of the procedure, leading to possible further extension to this specific combination of experimental designs to other substrates or even to other synthetic processes of industrial interest.

An integrated approach, based on quantitative transmission mode powder X-ray diffraction (PXRD) combined with multivariate statistical analysis, has been applied to cellulose obtained from three different sources to correlate the mercerization degree and crystallinity with the cellulose type, temperature, and reaction time. The effects of the experimental conditions on the two outcomes were studied by design of experiments (DoE) and surface responding analysis (SRA) combined with principal component analysis (PCA). SRA showed a marked influence of the type of cellulose (wood cellulose from the kraft vs. sulfite process, WCK vs. WCS) on the conversion of cellulose I to cellulose II (CII%) during mercerization. A counterintuitive simultaneous effect of temperature and cellulose type was also highlighted. The data elaboration in the form of response surface plots provided an easy predictive tool for the optimum conditions to maximize the conversion. The simulation reported for WCK showed maximum conversion (96%) at 70 &deg, C in 24 h with 18%wt NaOH.

UV&ndash, VIS spectroscopy analysis of six mixtures containing choline chloride or triphenylmethylphosphonium bromide as the hydrogen bond acceptor (HBA) and different hydrogen bond donors (HBDs, nickel sulphate, imidazole, d-glucose, ethylene glycol, and glycerol) allowed to determine the indirect and direct band-gap energies through the Tauc plot method. Band-gap energies were compared to those relative to known choline chloride-containing deep band-gap systems. The measurements reported here confirmed the tendency of alcohols or Lewis acids to increment band-gap energy when employed as HBDs. Indirect band-gap energy of 3.74 eV was obtained in the case of the triphenylmethylphosphonium bromide/ethylene glycol system, which represents the smallest transition energy ever reported to date for such kind of systems.

The optical properties of nine choline-based Deep Eutectic Solvents (DESs) of the type choline+X− (X− = chloride or acetate)/Y (Y = ethylene glycol, glycolic or levulinic acid) were studied by measuring their band gap through the UV-VIS-based Tauc method. All the considered systems showed a direct optical transition. A correlation between band gap and eutectic composition was discovered by plotting the variation of the band gap versus the molar fraction of choline+X−/Y in the parent systems containing 10 wt% of H2O. The main parameters influencing the energy of the optical transition in these “Deep Band Gap Systems” (DeBaGS) where studied through Design of Experiments (DoE) combined with multivariate analysis. The effect on the band gap of the anion (chloride or acetate), the acid (levulinic or glycolic), the water, and the stirring time, considered as single factor or in combination was clarified. Thus a multivariate model was implemented through surface responding analysis which allows engineering such kind of systems and opening to further applications in material science.

The identification and quantification of free fatty acids (FFA) in edible and non-edible vegetable oils, including waste cooking oils, is a crucial index to assess their quality and drives their use in different application fields. NMR spectroscopy represents an alternative tool to conventional methods for the determination of FFA content, providing us with interesting advantages. Here the approaches reported in the literature based on 1H, 13C and 31P NMR are illustrated and compared, highlighting the pros and cons of the suggested strategies.

The reduction of ketones through homogeneous transfer hydrogenation catalyzed by transition metals is one of the most important routes for obtaining alcohols from carbonyl compounds. The interest of this method increases when opportune catalytic precursors are able to perform the transformation in an asymmetric fashion, generating enantiomerically enriched chiral alcohols. This reaction has been extensively studied in terms of catalysts and variety of substrates. A large amount of information about the possible mechanisms is available nowadays, which has been of high importance for the development of systems with excellent outcomes in terms of conversion, enantioselectivity and Turn Over Frequency. On the other side, many mechanistic aspects are still unclear, especially for those catalytic precursors which have shown only moderate performances in transfer hydeogenation. This is the case of neutral [RuCl2(η6-arene)(P)] and cationic [Rh(PP)2]X (X = anion; P and PP = mono- and bidentate phosphine, respectively) complexes. Herein, a summary of the known information about the Transfer Hydrogenation catalyzed by these complexes is provided with a continuous focus on the more relevant mechanistic features.

Neutral dimeric rhodium diphosphine complexes are often employed as catalytic precursors in the presence of the solvent CH2Cl2. The possibility of a collateral reaction between the solvent and the catalytic precursor is never considered as the activation of CH2Cl2 by [Rh2(PP)2 (μ2-Cl)2] complexes is reputed difficult and uncommon. Herein we report the easy formation of three neutral dimeric Rh(III) complexes containing DPPP, DPPB and TangPhos through CH2Cl2 activation as an extension of the few examples reported so far. The system [Rh2 (DPPP)2 (μ2-Cl)2]/CH2Cl2 has been selected for a detailed mechanistic investigation. Kinetic studies based on 31P NMR monitoring combined with metathesis experiments reveal the fundamental role of a 14-electron intermediate [Rh(PP)Cl], which is involved in the CH2Cl2 activation.

The chemical composition and the color of samples of waste cooking oils (WCOs) were determined prior to and after filtration on two different pads of bentonite differing in particle size. The volatile fraction was monitored by headspace solid-phase microextraction (HS-SPME) coupled with gas-chromatography, while the variation of the composition of the main components was analyzed by 1H NMR. Both techniques allowed the detection of some decomposition products, such as polymers, terpenes, and derivatives of the Maillard process. The analysis of the chemical composition prior to and after bentonite treatment revealed a tendency for the clays to retain specific chemical groups (such as carboxylic acids or double bonds), independent of their particle size. A pair comparison test was conducted in order to detect the sensory differences of the intensity of aroma between the WCO treated with the two different bentonites. In addition, characterization of the bentonite by means of powder X-ray diffraction (XRD) and thermogravimetric measurements (TG) was performed.

Samples of sunflower Waste Cooking Oils (WCOs) subjected to several cycles of frying were treated with water under four different combinations of temperature and pH. The variation of the chemical composition of the oil samples was monitored through headspace Solid-Phase Microextraction (HS-SPME) coupled with gas-chromatographic technique (GC), 1H NMR spectroscopy and ESI+ mass spectrometry measurements. The possibility to modify the chemical composition of the recycled vegetable oil by tuning the water treatment parameters was exploited for the designing of a mini-plant for the production of bio-lubricants. A full description of the proposed prototype is also reported.

Background:In a previous study, we synthesised a new spiroketal derivative, inspired to natural products, that has shown high antiproliferative activity, potent telomerase inhibition and proapoptotic activity on several human cell lines.Objective:This work focused on the study of in vivo antitumor effect of this synthetic spiroketal on a murine melanoma model. In order to shed additional light on the origin of the antitumor effect, in vitro studies were performed.Methods:Spiroketal was administered to B16F10 melanoma mice at a dose of 5 mg/Kg body weight via intraperitoneum at alternate days for 15 days. Tumor volume measures were made every 2 days starting after 12 days from cells injection. The effects of the spiroketal on tumor growth inhibition, apoptosis induction, and cell cycle modification were investigated in vitro on B16 cells. HIF1α gene expression, the inhibition of cells migration and the changes induced in cytoskeleton conformation were evaluated.Results:Spiroketal displayed proapoptotic activity and high antitumor activity in B16 cells with nanomolar IC50. Moreover it has shown to inhibit cell migration, to strongly reduce the HIF1α expression and to induce strongly deterioration of cytoskeleton structure. A potent dose-dependent antitumor efficacy in syngenic B16/C57BL/6J murine model of melanoma was observed with the suppression of tumor growth by an average of 90% at a dose of 5 mg/kg.Conclusion:The synthesized spiroketal shows high antitumor activity in the B16 cells in vitro at nM concentration and a dose-dependent antitumor efficacy in syngenic B16/C57BL/6J mice. The results suggest that this natural product inspired spiroketal may have a potential application in melanoma therapy.

A pulsed gradient spin echo experiment on [Rh2(1,3-bis-(diphenylphosphino)-propane)2(μ2-Cl)2] complex has been conducted in order to shed light on the supposed monomerisation process of [Rh2(diphosphine)2(μ2-Cl)2] complexes in solution. Such a process should generate a 14-electron [Rh(diphosphine)Cl] complex, which has only been postulated to date. Metathesis experiments on [Rh2(1,3-bis-(diphenylphosphino)-propane)2(μ2-Cl)2] and [Rh2(bis[2-(diphenylphosphino)phenyl]ether)2(μ2-Cl)2] complexes, analysed by 31P NMR, reveal that monomerisation of [Rh2(diphosphine)2(μ2-Cl)2] complexes is not restricted to the case of 1,3-bis-(diphenylphosphino)propane.

An unexpected reaction of pyridine with acetyl chloride to give N-acetyl-1,2 and 1,4-dihydropyridyl acetic acid (1, 2) in high yield and regioselectivity has been reported. The key step is the formation of a zwitterionic pyridinium ketene enolate. The effect of different activating agents on the reaction yield and selectivity has been studied. Platinum(IV) mediated hydrogenation of the corresponding methyl esters (7, 8) gave piperidine derivatives (9, 10). © 2014 Elsevier Ltd. All rights reserved.

Seven commercial Moroccan honeys were considered for chemical characterisation. Volatile fraction, total polyphenols content, antioxidant and antiradical activities were evaluated by employing different analytical methodologies. Several physical parameters such as refractive index, pH, water content, solids content and colour were measured. Volatile fraction revealed an abundant presence of cis- and trans-linalool oxide in the seven studied samples. The presence of high levels of compounds related to the Maillard reaction, like furfural and hydroxymethylfurfural, could be the result of thermal treatments used to liquefy commercial honeys or of long storage times. The CIE L*a*b*Cab*hab° chromatic coordinates confirmed the advanced stage of the Maillard reaction, showing L* values lower than the common values found for honey of similar typologies.

Numerous complex natural products containing spiroketals framework, with a wide range of important biological activities, have been isolated over the years from marine or terrestrial sources. Many groups investigated the possibility to reduce the complexity of spiroketal natural products while preserving their biological activity, showing that simple natural inspired spiroketals can be privileged scaffolds for new interesting lead compounds. We have synthesized a new structurally simplified spiroketal that has shown a potent antitumor activity against tumor cells of different nature and histotype. The simple spiroketalic structure of this compound has three stereocentres and its synthesis afforded a stereoisomeric mixture. We carried out the synthesis and the characterization of the stereoisomeric mixture, the stereoisomeric separation and the biological evaluation both of the stereoisomeric mixture and the enantiomerically pure spiroketals.

Reduction of 1,2-diaryl-substituted ethenes with Na metal in dry THF allowed easy access to a variety of 1,2-diaryl-1,2-disodiumethanes. These diorganometallic intermediates were elaborated into the corresponding 1,2-diarylethanes (aqueous work up), or cycloalkylated with 1,3-dichloropropanes. The last reaction led to a highly diastereoselective synthesis of trans-1,2-diaryl-substituted cyclopentanes.

Recycling of waste cooking oil represents a source of convenient raw materials for industry. Within the large number of products derived from the treatment of waste cooking oil, eco-friendly lubricants grown in importance during the last years. Recycling process for such application consists usually of acid or basic degumming followed by a filtration step. The effect of the specific type of acid degumming on the density and on the flash point of the recycled oil was evaluated employing full factorial design. Two mathematical equations were derived which allow to estimate respectively the density and the flash point of the recycled oil, depending on the: (a) pH of the washing solution, (b) oil/water ratio, (c) temperature of the system, and (d) the stirring time. Practical applications Recycle of waste cooking oil presents several advantages. Mainly it is beneficial for the environment and considered as mandatory by law in several countries, and could furnish a useful low price raw material for several kind of industries. Recently, a multitude of local small scale industries have based their business on this topic and the recycling process employed often consists in a degumming step followed by filtration. This article deals with the tuning of the main parameters of the degumming step related with the density and the flash point of the final product. These parameters are important especially for lubricant synthesis.

The regioselectivity of the reaction can be altered by choice of the activating agent: NaH for 1,2- or TMS-O-Tf for 1,4-selectivity.

The preparation of a series of half-sandwich ruthenium complexes, [RuCl2(η6-p-cymene)(P*)] (P* = S-PMeRR′) and [RuCl2(κ-P*-η6-arene)], containing P-stereogenic phosphines is reported. The borane-protected P-stereogenic phosphines have been obtained by addition of the (H3B)PMe2R (R = t-Bu (1), Cy (2), Fc (3))/sec-BuLi/(−)-sparteine adduct to benzyl halides, carbonyl functions, and epoxides with yields between 40 and 90% and ee values in the 70–99% range. Those containing an aryl secondary function have been used in the preparation of [RuCl2(η6-p-cymene)(P*)] complexes. Borane deprotection has been performed using HBF4, except for (H3B)PRMe(CH2SiMe2Ph) phosphines, where DABCO was used to avoid partial cleavage of the CH2–Si bond. In the case of (H3B)P(t-Bu)Me(CH2C(OH)Ph2) (1l) the dehydrated phosphine was obtained. The tethered complexes were obtained by p-cymene substitution in chlorobenzene at 120 °C, except for ferrocenyl-containing complexes, which decomposed upon heating. The presence of substituents i...

A family of eight neutral, pseudotetrahedral piano-stool ruthenium complexes C, of the type [RuCl2(p-cymene)(PArPhR)] (Ar = 1-naphthyl, 9-phenanthryl and 2-biphenylyl; R = Me, i-Pr, OMe, –CH2SiMe3 and –CH2SiPh3) have been prepared and characterised, including the X-ray crystal structure for C6 (Ar = 2-biphenylyl; R = i-Pr). These complexes catalyse the asymmetric hydrogen transfer reaction of acetophenone in refluxing 2-propanol in the presence of potassium tert-butoxyde, reaching full conversions and up to 45% ee after 24 h towards the S enantiomer of 1-phenylethanol. Cationic complexes formed upon treatment of C with one equivalent of AgSbF6 or (Et3O)PF6 are active in the cyclopropanation reaction of styrene and α-methylstyrene by ethyl diazoacetate. Low to moderate conversions (up to 58%), diastereoselectivities (up to 40% de), and moderate enantioselectivities (up to 69% ee) have been found. For both reactions, bulky complexes and C6 in particular lead to the best results.

Two groups of P-stereogenic monodentate phosphines containing pendant groups bearing functionalities capable of having secondary interactions, PArPhR (Ar = 2-[(2′,6′-dimethoxy)-1,1′-biphenylyl] and R = OMe (6) or Me (8)) and PMeR(CH2R′) (13, R = t-Bu or 14 R = Fc and R′ = SiMe3 (a), SiMe2Ph (b) or CH2(2-naphthyl) (c)) have been prepared in enantiomerically pure form by the Juge and Evans methodologies and characterised, including the crystal structure for the borane adduct of 12b. Reaction of the phosphines with the Pd dimer [Pd(η3-2-Me-allyl)(μ-Cl)]2 produced neutral allylic complexes C [PdCl(η3-2-Me-C3H4)P∗], which have been characterised in solution and shown to be a mixture of isomers with different absolute configuration at the Pd atom. After abstraction of the chloride ligand by AgBF4, the solutions of cationic complexes have been used as catalyst precursors in the hydrovinylation of styrene under mild conditions. Very good activities (up to 1015 h−1), moderate to good selectivities to 3-phenyl-1-butene and low to moderate enantioselectivities (