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Analysis of artworks and identification of their molecular components are of utmost importance for selecting proper conservation strategies and monitoring restoration. Accordingly, development of simple and readily applicable paint analysis assays is highly sought in conservation science and technology. We prepared transparent spin-coated films comprising polydiacetylene (PDA) derivatives upon poly(methyl methacrylate) (PMMA) substrates and employed the PDA/PMMA films for color analysis of organic constituents in painting materials. We show that distinct color transformations were recorded upon addition of paint compounds to different PDA films. Quantitative analysis revealed that the colorimetric transitions were dictated by the interactions between the diacetylene headgroups and the tested compounds. This study underscores the significance of the diacetylene headgroup for molecular discrimination and points to the possible uses of the PMMA-supported PDA films for colorimetric screening of organic components in painting materials.

The azetidinone core-structure offers a unique approach to the design and synthesis of new derivatives with unique biological properties. During the last two decades researches convincingly demonstrated that the prospect of structural modifications of monocyclic β-lactams with specific substituents is an effective procedure for the detection and improvement of important pharmacological effects different from antibacterial activity. As a matter of fact, new β-lactam compounds demonstrated biological activity as inhibitors of a wide range of enzymes. This review reports the latest developments on monocyclic β-lactam compounds activity as anticancer, antitubercular, HFAAH inhibitors, HDAC inhibitors, anti-inflammatory drugs (tryptase inhibitors), Cathepsin K inhibitors, and vasopressin inhibitors. We attempted to highlight the intertwined relationships between structural features and biological activities, by analysing groups anchored on the three positions of the azetidinone ring as sources of molecular diversity.

This article describes the toxic effects of imidazolium ionic liquids bearing alkyl (BMIM), monoethoxy (MOEMIM), and diethoxy (M(OE)(2)MIM) side chains toward two marine diatoms, Skeletonema marinoi and Phaeodactylum tricornutum. MOEMIM and M(OE)(2)MIM cations showed a lower inhibition of growth and photosynthetic efficiency with respect to their alkyl counter part, with both algal Species. However, a large difference in sensitivity was found between S. marinoi and P. tricornutum, the first being much more Sensitive to the action of ionic liquids than the second one. The effects of salinity on BMIM Cl toxicity toward S. marinoi revealed that a decrease from salinity 35 to salinity 15 does not influence the biological effects toward the alga. Finally, Fourier transform infrared (FT-IR) microscopy of alga cells after ionic liquids exposure allowed us to detect an alteration of the organic cellular components related. to silica uptake and organization. On the basis of these results, the different behavior of the two diatom species can be tentatively ascribed to different silica uptake and organization in outer cell walls

Since the 1990s red-tide blooms of Fibrocapsa japonica have frequently been observed in European waters; despite their recurrence also in the Adriatic coastal areas, they have never been conclusively linked to ichthyotoxic events. Since the toxicity of F. japonica is still under debate and its effects differ among the strains, in this study all the compounds previously postulated as involved in the toxic mechanism, such as brevetoxins, fatty acids and ROS, were screened for Adriatic strains. Whole algal extracts were analyzed for brevetoxin PbTx-2, which was not found, and for a qualitative and quantitative analysis of fatty acids. The fatty acid profile evidenced the presence of PUFAs, with considerable amounts of 18:4n-3, 20:4n-6, and 20:5n-3, as already found in different strains, but with a lower amount of arachidonic acid (20:4n-6). None of the PUFAs was released in the extracellular medium. Different toxicological assays (Vibrio fischeri, Artemia sp., haemolysis of fish erythrocytes) were performed using algal cellular, extracellular or subcellular samples as well as fractions of the algal extract, in order to identify the toxic compounds. The tested cultures were found to inhibit V. fischeri bioluminescence, to affect Artemia nauplii viability and to have haemolytic effects comparable to those previously observed in different strains. The solid phase extraction (SPE) of the Adriatic F. japonica extracts resulted in a high concentration of PUFAs in two main fractions, which caused mortality in Artemia nauplii and inhibition of V. fischeri bioluminescence. Fish (Dicentrarchus labrax) assays were also performed, reporting mortality after long exposure times and the cause of fish death was investigated. A significant increase of H2O2 in the tanks where sea basses were exposed to F. japonica was obtained, indicating that the presence of fish stimulates H2O2 production by algal cells and leading to the hypothesis of H2O2 involvement in F. japonica toxicity. The presence of oxidative stress in the exposed fish was confirmed by the increased malondialdehyde concentration in their gills. Overall these results indicate that since F. japonica cells can easily cling to fish gills, due to their high polysaccharide production, it is presumable that high PUFA amounts are released in loco, as a result of cell breakage, and that exert their toxicity together with ROS. This study shows that the Adriatic strains of F. japonica can be harmful to higher level organisms. Nevertheless a high cell density and a long lasting bloom are necessary to cause severe damage to fish gills or death for crustaceans.

Lipid extraction is a critical step in the development of biofuels from microalgae. Here a new procedure was proposed to extract hydrocarbons from dried and water-suspended samples of the microalga Botryococcus braunii by using switchable-polarity solvents (SPS) based on 1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU) and an alcohol. The high affinity of the non-ionic form of DBU/alcohol SPS towards non-polar compounds was exploited to extract hydrocarbons from algae, while the ionic character of the DBU-alkyl carbonate form, obtained by the addition of CO(2), was used to recover hydrocarbons from the SPS. DBU/octanol and DBU/ethanol SPS were tested for the extraction efficiency of lipids from freeze-dried B. braunii samples and compared with n-hexane and chloroform/methanol. The DBU/octanol system was further evaluated for the extraction of hydrocarbons directly from algal culture samples. DBU/octanol exhibited the highest yields of extracted hydrocarbons from both freeze-dried and liquid algal samples (16% and 8.2% respectively against 7.8% and 5.6% with n-hexane).

The synthesis of halo- and dihalovinyl-β-lactams by a halodecarboxylation reaction has been developed. Optimized procedures gave good yields of dibromo-, iodo- and diiodovinyl derivatives. The unprecedented synthesis of dihalo compounds by a Hunsdieker reaction was investigated in detail by 1H NMR analysis, which allowed the formulation of a reaction mechanism and revealed the role of triethylamine as a deiodinating agent. The dibromo- and diiodoalkylidene-β-lactams obtained were tested in a cross-coupling reaction with dimethylzinc. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

6-Aminopenicillanic acid (6-APA) and two of its derivatives, 6-APA benzyl ester (6-APA-OBn) and Penicillin G (PenG), have been evaluated as catalysts for use in direct cross-aldol reactions in different solvents and mixtures. The effects of catalyst loading, reaction time, pH and temperature on the yield and stereoselectivity have been studied. 6-APA proved to be an effective catalyst in terms of yield for the reaction between cyclohexanone and p-nitrobenzaldehyde, especially in neat conditions. The stereoselectivity of the reaction was conditioned by the presence of two competing mechanisms: one an imine–enamine pathway and the other a Bronsted acid catalysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

We report the first temperature study on the stereoselectivity of the ‘in-water’ aldol reaction between nicotinaldehyde (3-pyridinecarbaldehyde) and cyclohexanone catalyzed by morpholine and trans -4- tert -butyldimethylsilyloxy- l -proline. Eyring plots of diastereomeric ratio anti / syn gave a constant diastereoselectivity with respect to reaction temperature using morpholine as catalyst. With O(TBS)- l -proline we observed a non-linear behaviour of the Eyring plot with the presence of an inversion temperature ( T inv ), which disclosed dynamic solvation effects in water.

Oil wastes and slops are complex mixtures of hydrocarbons, which may contain a variety of contaminants including tetrachloroethylene (perchloroethylene, PCE) and other volatile halogenated organic compounds (VHOCs). The analytical determination of PCE at trace levels in petroleum-derived matrices is difficult to carry out in the presence of large amounts of hydrocarbon matrix components. In the following study, we demonstrate that headspace solid-phase microextraction (HS-SPME) combined with GC–MS analysis can be applied for the rapid measurement of PCE concentration in oil samples. The HS-SPME method was developed using liquid paraffin as matrix matching reference material for external and internal calibration and optimisation of experimental parameters. The limit of quantitation was 0.05 mg kg−1, and linearity was established up to 25 mg kg−1. The HS-SPME method was extended to several VHOCs, including trichloroethylene (TCE) in different matrices and was applied to the quantitative analysis of PCE and TCE in real samples.

The synthesis of a new family of halogenated β-lactams by oxidative substitution of vinylic hydrogen in conjugated double bonds of 4-alkylidenazetidinones is reported. Optimised procedures give good to excellent yields of chloro, bromo, iodo and nitro derivatives. A mechanism to explain the direct vinylic substitution is proposed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

The αvβ3 and α5β 1 integrins are widely expressed in different cancer types and recognize the tripeptide Arg-Gly-Asp (RGD) motif present in several extracellular matrix proteins. We report here the design, synthesis and biological activity of some new β-lactam derivatives specifically designed to target integrins. The new molecules contain the azetidinone as the only cyclic framework armed with carboxylic acid and amine terminals spaced from 9 to 14 atoms to switch on recognition by integrins. All tested molecules showed a concentration-dependent enhancement in fibronectin-mediated adhesion of K562 and SK-MEL-24 cells; in particular 1, expressed a higher affinity towards α5β1 integrin (EC50 of 12 nM) and 2 was more selective for integrin αvβ3 (EC 50 of 11 nM). © 2014 Elsevier Masson SAS. All rights reserved.

Comb polyelectrolytes (CPs) having neutral hydrophilic teeth, similar to double hydrophilic block copolymers, are a powerful tool to modify the chemical-physical properties of inorganic crystalline materials. One of their main applications is in concrete technology, where they work as superplasticizers, particle-dispersing agents. Here, CPs, having the same poly(acrylic acid) (PAA) backbone chain and differing in the grafting with methoxy poly(ethylene glycol) chains (MPEG) of two molecular weights, were used to investigate the influence of tooth chains in polymer aggregation and in control on morphology and aggregation of calcite particles. These polymers aggregate, forming interpolymer hydrogen bonds between carboxylic groups and ether oxygen functionalities. The presence of calcium ions in solution further enhances aggregation. Crystallization experiments of calcite in the presence of CPs show that the specificity of interactions between polymers and crystal planes and control on aggregation and size of particles is a function of the content and chain length of the MPEG in the PAA backbone. These parameters limit and can make specific the electrostatic interactions with ionic crystalline planes. Moreover, the mechanism of crystallization, classical or nonclassical, is addressed by the CP structure and concentration. These findings have implications in the understanding of the complex chemical processes associated to concrete superplasticizers action and in the study of the biomineralization processes, where biological comb polyelectrolytes, the acidic glycoproteins, govern formation of calcitic structures.

Pyrrolidinium imides are considered among the most promising electrolytes for the development of novel and sustainable portable energy devices. Because of this widespread potentiality, a risk scenario of an erroneous disposal of ionic liquids-based batteries in the environment has to be taken into account. In the present study, some of the best energy performing pyrrolidinium-based ionic liquids were evaluated in terms of persistence in aquatic environments and hazard toward freshwater organisms (crustacean Daphnia magna and unicellular green alga Raphidocelis subcapitata). The examined ionic liquids were not aerobically biodegradable (biodegradation less than 5% in 28 days), but they demonstrated low toxicity toward algae and crustaceans, according to the standard bioassay end points (EC50 > 100 mg L-1). However, ionic liquids were able to alter the cellular morphology of R subcapitata and an increased amount of proteins (30%) was observed in the exposed cells, suggesting an inhibition of cellular division.

A new class of glycoconjugated β-lactams was accessed by direct glycosidation of a suitable 4-alkylidene-azetidin-2-one acceptor with several perbenzylated (N-phenyl)trifluoroacetimidate donors activated by catalytic Yb(OTf)3. Goodstereocontrol was achieved by relying on the stereo directing effect of nitrile or ether solvents. Transfer hydrogenolysis under carefully controlled conditions enabled the removal of the benzyl group without affecting the β-lactam double bond. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

beta-Lactams, a well known class of antibiotics, have been investigated as inhibitors of the disruptive protease released by inflammatory cells, leukocyte elastase (LE). We have synthesized a new beta-lactam with an N-linked galloyl moiety, the latter identified as strategic in conferring anti-LE properties to some flavonols. This N-galloyl-derivative beta-lactam inhibits the LE activity with a K(i) of 0.7 microM, whereas it exerts weak activity against cathepsin G and protease-3 (IC(50)100 microM), and matrix metalloproteinase (MMP)-2 and MMP-9. Without affecting chemotactic response and viability of polymorphonuclear (PMN) leukocytes, the compound efficiently restrains their chemoinvasion (IC(50) of 1-2 microM) blocking the LE-triggered activation of pro-MMP-9, instrumental to extravasation. Daily i.p. injection of compound enhances resolution in a pulmonary inflammation model, significantly reducing consequent fibrosis. These results indicate that the new beta-lactam is a potent anti-inflammatory compound with therapeutic potential.

EDDHSA/Fe is a promising substitute of EDDHA/Fe to fight iron chlorosis. o,o-EDDHSA structure contains two chiral carbons giving the racemic and meso couples of stereoisomers. Ion-pair HPLC and UHPLC–UV/Vis–ESI-MS/MS methods were developed for the determination of racemic and meso-o,o-EDDHSA/Fe in commercial samples of chelates. The lack of a commercial EDDHSA standard was overcome by sulfonation of a commercial available o,o-EDDHA standard and subsequent quantification by 1H-NMR. Assignment of configurations was carried out starting from racemic and meso-o,o-EDDHA/Fe by direct sulfonation to give the corresponding o,o-EDDHSA/Fe isomers. The performances of these methods were assessed in terms of intra and inter-day precision, linearity and selectivity. The high selectivity and lower detection limit (nanomolar) of the UHPLC–ESI-MS/MS method could allow to deepen the knowledge relative to meso and rac-o,o-EDDHSA/Fe interactions with plants, its fate in different soil conditions, its mobility and other environmental aspects.

In addition to their antibiotic potency, beta-lactams have recently been investigated as inhibitors of serine proteinase such as leukocyte elastase (LE), released by inflammatory cells. We describe the synthesis of a series of 4-alkylidene-beta-lactams, and investigate how substitutions on C-3, C-4, and N-1 of the beta-lactam ring affect the activity of human LE and gelatinases MMP-2 and MMP-9. LE activity was measured using a chromogenic substrate, while gelatin-zymography assay was used to evaluate gelatinase activity. We demonstrate that C-4 unsaturation on the beta-lactam ring determines the degree of biological activity, with a selectivity over LE by 3-[1-(tert-butyldimethylsilyloxy)-ethyl] derivatives (lowest IC(50) was 4 microM), and over gelatinase MMP-2 by C-3-unsubstituted 4-[1-ethoxycarbonyl]-ethylidene-beta-lactams (lowest IC(50) was 60 microM). (3S)-3-[(1R)-1-hydroxyethyl]-4-(1-ethoxycarbonyl)-ethylidene-azetidin-2-one inhibits gelatinase MMP-9. The compounds tested showed no cytotoxicity against NIH-3T3 murine fibroblasts. This is the first example of beta-lactams inhibiting metallo-proteinases instrumental in cancer invasion and angiogenesis. These molecules are good candidates for prototype drugs showing selective antibiotic, anti-inflammatory, and anti-invasion properties.

The enantiomeric ratio E of enzyme-catalyzed (Candida antarctica lipase and lipase PS) and chemo-catalyzed (L-proline-based diamines) acylation reactions of 1-(naphthalen-2-yl)ethanol, 2-phenylpropanol, and 2-benzylpropane-1,3-diol is dependent on solvent and temperature. Plots of ln E vs. 1/T showed the presence of inversion temperatures (Tinv). The Tinv values for the bio-catalyzed and the chemo-catalyzed reactions are fairly in agreement, and correspond as well to the TNMR values obtained by variable-temperature 13C-NMR experiments on the substrates in the same solvent of the resolution. This result demonstrates that clustering effects in the substrate solvation manage the chemical and the enzymatic enantioselectivity, and, moreover, that the solutesolvent cluster is always the real reacting species in solution for chemical as well as for enzymatic reactions.

We report the synthesis of a class of 4-(2-oxoethylidene)azetidin-2-ones by a novel Lewis acid mediated reaction of acyldiazo compounds with 4-acetoxyazetidin-2-ones. Using this approach, C-3-and C-4-substituted 4-alkylideneazetidin-2-ones were obtained depending on the choice of starting azetidinone and α-diazocarbonyl compound. The products reveal excellent Z diastereoselection of the C-4 double bond. Variable amounts of E isomers are obtained depending on the nature of the C-3 side chain, the Lewis acid, and the β-lactam protection. VT NMR spectroscopic experiments and X-ray structural analysis of crystalline derivatives demonstrate the presence of an intramolecular hydrogen bond in Z isomers, which drives the stereochemical outcome of the reaction. A possible mechanism for this novel reaction is proposed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Temperature-dependent selectivity in nucleophilic additions to α-chiral aldehydes is affected by solvent mixtures. In this context, we investigated the effect on diastereoselectivity of tertiary amines as co-solvents. Addition of 5 mol% of an amine to hexane strongly influences the anti/syn ratio in the additions of nBuLi to 2-phenylpropanal and to (2S)-2-[(tert-butyl)dimethylsilyloxy]-2-propanal. In these hexane/amine mixtures as reaction solvents, we observed diastereoselectivities higher than those obtained in hexane. In the corresponding Eyring plots of ln(anti/syn) against the reciprocal temperature, we observed inversion temperatures (Tinv), these generally occurring at higher temperatures in the hexane/amine mixtures than in pure hexane. The presence of the inversion temperatures confirms that these tertiary amines take part in the solvation of the starting aldehyde, thus contributing to a solvent effect on facial selectivity. In some cases, the differential entropy of activation is the predominant factor in differentiating the diastereoselectivity among these hexane/amine mixtures. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

The ability of integrins to activate and integrate intracellular communication illustrates the potential of these receptors to serve as functional distribution hubs in a bi-directional signal transfer outside-in and inside-out the cells. A tight regulation of the integrin signalling is paramount for normal physiological functions such as migration, proliferation, and differentiation and a misregulated integrin activity could be associated with several pathological conditions. Because of the important roles of integrins and their ligands in biological development, immune responses, leukocyte traffic, haemostasis, and cancer, their potential as therapeutic tools is now widely recognized. Nowadays extensive efforts have been made to discover and develop small molecule ligands as integrin antagonists whereas less attention has been payed to agonists. In recent years, it has been recognized that integrin agonists could open up novel opportunities for therapeutics, which gain benefits to increase rather than decrease integrin-dependent adhesion and transductional events. For instance, a significant factor in chemo-resistance in melanoma is a loss of integrin-mediated adhesion; in this case, stimulation of integrin signalling by agonists significantly improved the response to chemotherapy. In this review, we overview results about small molecules which revealed an activating action on some integrins, especially those involved in cancer, and to examine from a medicinal chemistry point of view their structure and behavior.

Polyhydroxyalkanoates (PHAs) can be extracted from mixed microbial cultures (MMCs) by means of dimethyl carbonate (DMC) or combination of DMC and sodium hypochlorite (NaClO). The protocol based on DMC, a green solvent never used before for the extraction of PHAs from MMC, allows an overall polymer recovery of 63%; also the purity and the molecular weight of the recovered polymers are good (98% and 1.2 MDa, respectively). The use of NaClO pretreatment before DMC extraction increases the overall PHA recovery (82%) but lowers the mean molecular weight to 0.6–0.2 MDa. A double extraction with DMC results to be the method of choice for the recovery of high quality PHAs from attractive but challenging MMCs.

The diastereofacial selectivity of (2S)-O-(tert-butyldimethylsilyl)lactal towards nucleophilic addition of ethylmagnesium bromide is strongly solvent-dependent. We have shown that solute−solvent interactions occurring in a series of ethers, such as tetrahydrofuran, tetrahydropyran, diethyl ether, dipentyl ether, tert-butyl methyl ether, diisopropyl ether, diisopentyl ether, and anisole, can govern a diastereomeric switch from the anti to the syn isomer. Determination of the temperature-dependence of the anti/syn ratio has enabled the selectivity to be analysed in terms of the differential enthalpies and entropies of activation of the two diastereomeric reaction paths. We have demonstrated that the predominance of one isomer over the other is often due to an entropy effect on the diastereofacial selectivity. The phenomenon of the inversion temperature was evident in the corresponding Eyring plots.

Temperature dependence measurements allow the evaluation of stereoselectivity in terms of differential enthalpy and entropy of activation. An analysis of diastereoselectivity in the addition reaction of nBuLi to O-protected α-hydroxy aldehydes revealed the great importance of the entropic contribution in directing the facial diastereoselectivity. In many cases, the resulting Eyring plots show an inversion temperature (Tinv). The existence of the Tinv as well as the enthalpic and entropic dominance of one diastereoisomer greatly depend on the reaction solvent.

Temperature-dependent selectivity in nucleophilic additions is affected by the solvent. The inversion temperature (marked with arrows in the graph) that appears in the nonlinear Eyring plots of ln (anti/syn) versus temperature for the addition of butyllithium to an O-protected alpha-hydroxy aldehyde 1 does not depend on nucleophiles (nBuLi (black triangle), tBuLi (*)), but on the solvent. Its value can be obtained from a plot of the (13)C NMR chemical shift of C=O versus temperature. TBDMS=tBuMe(2)Si.

Solvent and temperature effects on facial diastereoselectivity of nucleophilic addition have been long observed but often neglected. Temperature dependent measurements according to the modified Eyring equation allow the evaluation of stereoselectivity in terms of differential enthalpy and entropy of activation, and demonstrate the paramount importance of entropic contribution in directing the facial diastereoselectivity. Even the reaction solvent proved to be important in determining the isomer ratio. In many cases Eyring plots show a non-linear behavior consisting of two linear regions intersecting at a point called the inversion temperature (Tinv) which, for the same reaction, depends on the nature of the solvent and correlates with their melting points. We propose that Tinv is the temperature value for the interconversion between two different solvation clusters which should behave like two different molecules.

Synthesis of 3-vinyl- and 3-alkyl-Δ3-cephems was performed in a regioselective manner by palladium acetate catalyzed reaction of 3-sulfonato- or 3-bromo-Δ3-cephems with dialkylzinc or vinyltributyltin. A new access to 3-alkyl-Δ3-cephems is opened, starting from the allenyl compound 10.

N -( p -methoxyphenyl)-hexahydro-1,3,5-triazine in presence of a Lewis acid and ( R )-3-( t -butyldimethylsilyloxy)butyric acid chloride with Et 3 N directly furnish (3 S ,1′ R )- N - p -methoxyphenyl-3-(1- t -butyldimethylsilyloxy)ethylazetidin-2-one with good diastereo-selectivity. This product is transformed into the 4-acetoxy-azetidinone 1 , a key intermediate in the synthesis of β-lactam antibiotics.

A detailed study of the influence of temperature, pH and enzyme amount on the enantiomeric excess in the enzymatic resolution of N -1 protected 3-amino-azetidin-2-ones with supported PGA is presented. Both enantiomers could be obtained in good enantiomeric excess.

A new synthesis of a series of new chiral α-aminonitriles derived from L-α-amino acids is described.

As a part of a systematic investigation on the synthesis and biological activities of new β-lactam compounds, we examined β-lactam candidates 1, 2E and 2Z and their ability to induce cell proliferation or differentiation. Azetidinone 1 was chosen for its activity (previously evaluated) as selective HDAC8 inhibitor, whereas β-lactams 2E and 2Z were designed to have a hybrid retinoid-azetidinone structure, de novo synthesized and fully characterized. Biological activities were determined in cellular assays on neuroblastoma cells SH-SY5Y. Azetidinone 1, 2E and 2Z led to a moderate effect in decreasing SH-SY5Y cell proliferation and β-lactams 2E and 2Z induced an early stage differentiation. The present results uncovered a new role of specifically designed β-lactam compounds in epigenetic regulation.

The novel histidine-tagged Horse Liver Alcohol Dehydrogenase (His-HLADH-EE) was successfully purified and covalently immobilized onto a solid support in a one-step procedure through a metal-directed technique. A full characterization of the immobilized enzyme was carried out. Effects of pH, temperature and organic co-solvents were deeply investigated and they showed a shift in the optimum pH with respect to the free form as well as increased stability to temperature and solvents. The immobilized His-HLADH-EE proved to be effective as catalyst in the reduction of aliphatic and aromatic aldehydes. Application of the free and immobilized His-HLADH-EE to the chemo-enzymatic synthesis of (S)-Profenols demonstrated enhanced enantioselectivity and high reusability of the immobilized form. The achievement of a robust and effective immobilization of an alcohol dehydrogenase substantiated the use of biocatalytic reduction in the synthesis of primary alcohols and valuable chiral intermediates especially for pharmaceutical industries. Irish Research Council for Science, Engineering and Technology Ircset the Italian Ministry of Education, University and Research (MIUR), and University of Bologna Author has checked copyright kpw19/6/13

A series of N-methylthio-beta-lactams with antibacterial activity were thoroughly evaluated as antioxidants. We found that only the presence of a polyphenolic moiety anchored to the beta-lactam ring ensured an adequate antioxidant potency. New compounds, efficiently combining in one structure antioxidant and antibacterial activity, may provide a promising basis for the development of new leads useful in adverse clinical conditions such as in cystic fibrosis patients, in whom colonization by MRSA and epithelial damage by chronic pulmonary oxidative stress take place.

The cyanosilylation of a series of N-substituted lactaldehyde imines is reported. The trimethylsilylcyanide addition affords optically active α-amino nitriles. All the imines show a syn diastereofacial selectivity that is maintained irrespective to the nature of the Lewis acid employed and even remains in the noncatalyzed reaction.

New polyethoxylated tertiary amines were synthesised and applied as Switchable Hydrophilicity Solvents (SHS) in the extraction and recovery of lipids from algal cultures, bypassing harvesting and de-watering steps. The eco-toxicological profile of the new amines was explored by evaluating their potential in inhibiting algal growth, and deepened by measuring the acute toxicity towards the crustacean Daphnia magna and the ready biodegradability in water. Among the synthesised amines, the one bearing two ethoxy units, named amine 2, showed the best combination in terms of lipids' extractive performances and toxicity; therefore it could be considered as a good alternative to N,N-dimethylcyclohexylamine (DMCHA), at the moment the most studied and effective SHS. © 2014 The Royal Society of Chemistry.

Acid catalysts were prepared by sulfonation of carbon materials obtained from the pyrolysis of sugar beet molasses, a cheap, viscous byproduct in the processing of sugar beets into sugar. Conditions for the pyrolysis of molasses (temperature and time) influenced catalyst performance; the best combination came from pyrolysis at low temperature (420 °C) for a relatively long time (8-15 h), which ensured better stability of the final material. The most effective molasses catalyst was highly active in the esterification of fatty acids with methanol (100 % yield after 3 h) and more active than common solid acidic catalysts in the transesterification of vegetable oils with 25-75 wt % of acid content (55-96 % yield after 8 h). A tandem process using a solid acid molasses catalyst and potassium hydroxide in methanol was developed to de-acidificate and transesterificate algal oils from Chlamydomonas reinhardtii, Nannochloropsis gaditana, and Phaeodactylum tricornutum, which contain high amounts of free fatty acids. The amount of catalyst required for the de-acidification step was influenced by the chemical composition of the algal oil, thus operational conditions were determined not only in relation to free fatty acids content in the oil, but according to the composition of the lipid extract of each algal species.

Treatment of (3R,4R,1′R)-3-[1-(t-butyldimethylsilyloxy)ethyl]-4-acetoxy-azetidin-2-one with ethyl diazoacetate in the presence of a Lewis acid such as TiCl4, TiF4, AlCl3 or SnCl4 affords the novel (3S,1′R)-3-[1-(t-butyldimethylsilyloxy)ethyl]-4(1-ethoxycarbonyl-methylidene)-azetidin-2-one as an E and/or Z isomer.

The use of acetone cyanohydrin for the one-pot Strecker reaction in water under catalyst-free conditions is described.

In this paper the expected environmental impacts of the industrial cellulose dissolution with the ionic liquid 1-butyl-3-methylimidazolium chloride (Bmim Cl) were analyzed through a “cradle to gate” Life Cycle Assessment (LCA). In order to weigh up the “greenness” of the process, the analysis was performed through a comparison with the well established environmental friendly N-methyl-morpholine-N-oxide (NMMO)/H2O process. Although dissolution of cellulose in Bmim Cl has not been used for industrial production of cellulose fibers to date, results from LCA suggest that it could be interesting from an environmental point of view since its impacts are similar to those of the NMMO/H2O process. Specifically, the process with Bmim Cl generates a higher environmental load on abiotic resource depletion, emissions of volatile organic compounds and ecotoxicity than the NMMO/H2O process. Conversely it has some environmental advantages with regards to human toxicity. In both cellulose dissolution processes, the major contributions to the environmental impacts come from precursor syntheses. In addition to the comparative analysis of the two cellulose dissolution processes, the paper reports the complete life cycle inventory (LCI) of the two solvents, Bmim Cl and NMMO, and their life cycle impact assessment (LCIA).

A simple, convenient, and practical method for the synthesis of alpha-amino nitriles through a one-pot, three-component Strecker reaction of a carbonyl compound, amine, and acetone cyanohydrin in water has been developed. Reactions proceed very efficiently without any catalyst at room temperature with high chemoselectivity and give, in some cases, the expected a-amino nitrile pure after direct separation from water. The protocol is particularly efficient for both aliphatic and aromatic aldehydes, and cyclic ketones, in combination with primary and secondary amines. An unusual application of the Strecker reaction to 1,2-diamines to obtain 1,2-diamino nitriles, and to cyclic secondary amines is reported.

The increasing emergence of multidrug-resistant microorganisms is one of the greatest challenges in the clinical management of infectious disease. New antimicrobial agents are therefore urgently required, particularly in the treatment of chronic and recurrent infections often associated with antibiotic-resistant pathogens, as in the case of cystic fibrosis (CF) patients. This study reports the antibacterial activity of a series of monocyclic beta-lactams with an alkylidenecarboxyl chain or electron-withdrawing groups such as 4-OAc, 4-SAc, and 4-SO(2)Ph at the C4 position of the ring. N-Unsubstituted and N-thiomethyl derivatives were compared. A total of 33 azetidinones were tested for their activity against Gram-positive and Gram-negative bacterial clinical isolates. The combination of an N-thiomethyl group and a benzyl ester on the 4-alkylidene side chain were found to increase the potency against Gram-positive bacteria. The N-thiomethyl group clearly elevated the activity of 4-acetoxyazetidinones relative to the corresponding NH derivatives. The most active compounds showed minimum inhibitory concentration (MIC) values of 4 and 8 mgL(-1) against methicillin-resistant Staphylococcus aureus isolated from pediatric patients with CF.

The cyanosilylation of a series of N-substituted lactaldehyde imines is reported. The trimethylsilylcyanide addition affords optically active α-amino nitriles. All the imines show a syn diastereofacial selectivity that is maintained irrespective to the nature of the Lewis acid employed and even remains in the noncatalyzed reaction.