Evaluation of Effective Composite Biosorbents Based on Wood Sawdust and Natural Clay for Heavy Metals Removal from Water.

Bentonitic clay and wood sawdust are natural materials widely available in nature at low cost with high heavy metals sorption properties that, in this work, were combined to achieve an effective composite biosorbent with high sorption properties and enhanced mechanical stability. Pine, aspen, and birch wood sawdust, as well as different bentonite clays and different sawdust modification methods (HPO or HCl) were used for preparing new composite biosorbents. A mixture of wood sawdust and bentonite in a ratio of 2:1 was used.

Urinary l-kynurenine quantification and selective extraction through a molecularly imprinted solid-phase extraction device.

l-Kynurenine is an endogenous metabolite generated by the catabolic pathway of l-tryptophan and it could be a potential biomarker to test the efficacy of several checkpoint inhibitors that have already reached the clinical trials in the antitumor therapy. Thus, a molecularly imprinted polymer specific for the recognition of this metabolite was synthesized and used as innovative system in solid-phase extraction technique for the specific extraction and quantification of l-kynurenine in human urine. The off-line system was firstly tested on l-kynurenine standard solutions, allowing recoveries up to 97.

Molecularly Imprinted Composite Membranes for Selective Detection of 2-Deoxyadenosine in Urine Samples.

An important challenge for scientific research is the production of artificial systems able to mimic the recognition mechanisms occurring at the molecular level in living systems. A valid contribution in this direction resulted from the development of molecular imprinting. In this work, a novel molecularly imprinted polymer composite membrane (MIM) was synthesized and employed for the selective detection in urine samples of 2-deoxyadenosine (2-dA), an important tumoral marker.

Photoreduction of carbon dioxide to formic acid in aqueous suspension: a comparison between phthalocyanine/TiO2 and porphyrin/TiO2 catalysed processes.

Composite materials prepared by loading polycrystalline TiO2 powders with lipophilic highly branched Cu(II)- and metal-free phthalocyanines or porphyrins, which have been used in the past as photocatalysts for photodegradative processes, have been successfully tested for the efficient photoreduction of carbon dioxide in aqueous suspension affording significant amounts of formic acid. The results indicated that the presence of the sensitizers is beneficial for the photoactivity, confirming the important role of Cu(II) co-ordinated in the middle of the macrocycles. A comparison between Cu(II) phthalocyanines and Cu(II) porphyrins indicated that the Cu(II)- phthalocyanine sensitizer was more efficient in the photoreduction of CO2 to formic acid, probably due to its favorable reduction potential.

Developments in the synthesis of a water compatible molecularly imprinted polymer as artificial receptor for detection of 3-nitro-L-tyrosine in neurological diseases.

A highly selective water compatible molecularly imprinted polymer (MIP) for 3-nitro-L-tyrosine (3NT), an oxidative stress marker associated with neurodegenerative disorders, was prepared and its use as solid-phase extraction (SPE) sorbent material was demonstrated. The MIP was prepared by bulk polymerization using methacrylic acid as functional monomer and acetonitrile as porogen with traces of acetic acid and trifluoroacetic acid. In order to evaluate its binding properties, the MIP was analyzed by batch rebinding experiments and subsequently used as SPE sorbent for the selective clean-up and pre-concentration of 3NT from standard solutions and spiked human urine samples.

Molecularly imprinted polymers: present and future prospective.

Molecular Imprinting Technology (MIT) is a technique to design artificial receptors with a predetermined selectivity and specificity for a given analyte, which can be used as ideal materials in various application fields. Molecularly Imprinted Polymers (MIPs), the polymeric matrices obtained using the imprinting technology, are robust molecular recognition elements able to mimic natural recognition entities, such as antibodies and biological receptors, useful to separate and analyze complicated samples such as biological fluids and environmental samples. The scope of this review is to provide a general overview on MIPs field discussing first general aspects in MIP preparation and then dealing with various application aspects.

Use of novel cardanol-porphyrin hybrids and their TiO₂-based composites for the photodegradation of 4-nitrophenol in water.

Cardanol, a well known hazardous byproduct of the cashew industry, has been used as starting material for the synthesis of useful differently substituted "cardanol-based" porphyrins and their zinc(II), copper(II), cobalt(II) and Fe(III) complexes. Novel composites prepared by impregnation of polycrystalline TiO₂ powder with an opportune amount of "cardanol-based" porphyrins, which act as sensitizers for the improvement of the photo-catalytic activity of the bare TiO₂, have been used in the photodegradation in water of 4-nitrophenol (4-NP), which is a toxic and bio-refractory pollutant, dangerous for ecosystems and human health.

Synthesis of molecularly imprinted polymers for amino acid derivates by using different functional monomers.

Fmoc-3-nitrotyrosine (Fmoc-3-NT) molecularly imprinted polymers (MIPs) were synthesized to understand the influence of several functional monomers on the efficiency of the molecular imprinting process. Acidic, neutral and basic functional monomers, such as acrylic acid (AA), methacrylic acid (MAA), methacrylamide (MAM), 2-vinylpyridine (2-VP), 4-vinylpyridine (4-VP), have been used to synthesize five different polymers. In this study, the MIPs were tested in batch experiments by UV-visible spectroscopy in order to evaluate their binding properties.

Cardanol-based materials as natural precursors for olefin metathesis.

Cardanol is a renewable, low cost natural material, widely available as a by-product of the cashew industry. It is a mixture of 3-n-pentadecylphenol, 3-(pentadeca-8-enyl)phenol, 3-(pentadeca-8,11-dienyl)phenol and 3-(pentadeca-8,11,14-trienyl)phenol. Olefin metathesis (OM) reaction on cardanol is an important class of reactions that allows for the synthesis of new olefins that are sometime impossible to prepare via other methods.

Synthesis of nicotinamide-based molecularly imprinted microspheres and in vitro controlled release studies.

Nicotinamide (NAM), which is one of the two principal forms, together with nicotinic acid, of vitamin B3, is both a food nutrient and a drug. Controlled NAM release systems are useful to extend the duration of the drug's pharmacological activity and to minimize administration frequency. In this paper, molecularly imprinted polymers (MIPs) have been used as unconventional synthetic polymeric carriers, to prepare drug delivery systems for sustained release of NAM molecules.

Molecularly imprinted polymers for solid-phase extraction of 1-methyladenosine from human urine.

A highly selective molecularly imprinted polymer (MIP) for 1-methyladenosine (1-MA), an urinary modified nucleoside used as cancer marker, was prepared and its use as solid-phase extraction (SPE) sorbent material was demonstrated. The MIP was prepared by a very simple procedure using methacrylic acid as functional monomer and a mixture acetonitrile/water (4/1, v/v) as porogen, overcoming in this way the problems usually related to the imprinting of biological polar compounds. The MIP was tested in batch experiments in order to evaluate its binding properties and then used as SPE sorbent for the selective clean-up and pre-concentration of 1-MA.

Degradation of 4-nitrophenol (4-NP) using Fe-TiO2 as a heterogeneous photo-Fenton catalyst.

Photocatalytic degradation of 4-nitrophenol was investigated using Fe-doped (1, 3, 5 and 8 wt.% Fe) TiO(2) catalysts under UV light irradiation in aqueous dispersions in the presence of H(2)O(2). Photocatalysts with the lowest Fe content (1%) showed a considerably better behavior with respect to the unloaded TiO(2) and the catalysts with higher Fe contents.

Rectification in supramolecular zinc porphyrin/fulleropyrrolidine dyads self-organized on gold(111).

Self-assembled donor/acceptor dyads are of current interest as they are biomimetic to the natural photosynthetic conversion system. Herein, we present an ultrahigh-vacuum scanning tunneling microscopy and scanning tunneling spectroscopy (UHV-STM/STS) study of ex situ self-assembled supramolecular dyads consisting of fulleropyrrolidines (PyC(2)C(60)) axially ligated to zinc(II) tetraphenylporphyrin (ZnTPP), self organized on a 4-aminothiophenol (4-ATP) self-assembled monolayer on gold(111). These dyads show both bias-polarity-dependent apparent height in STM images and highly rectifying behavior in tunneling spectroscopy.

Experimental and computational studies on non-covalent imprinted microspheres as recognition system for nicotinamide molecules.

Molecularly imprinted microspheres obtained by precipitation polymerization using nicotinamide (nia) as template have been prepared and characterised by SEM. How various experimental parameters can affect microsphere morphology, reaction yield and re-binding capacity have been evaluated. Pre-polymerization interactions between template and functional monomer in chloroform and MeCN have been studied by (1)H-NMR.

Autophagy inhibition enhances anthocyanin-induced apoptosis in hepatocellular carcinoma.

Anthocyanins extracted from the berries of Phillyrea latifolia L., Pistacia lentiscus L., and Rubia peregrina L.

Zinc porphyrin-driven assembly of gold nanofingers.

Nanofingers of gold covered by porphyrins are prepared by a combination of atomic manipulation and surface self-organization. A submonolayer of zinc(II) 5,10,15,20-tetrakis(4-tert-butylphenyl)-porphyrin (ZnTBPP) axially ligated to a self-assembled monolayer of 4-aminothiophenol (4-ATP) on Au(111) is prepared and studied using a combination of ultrahigh vacuum techniques. Under the electric field produced by the STM tip, the relatively weakly bound Au surface atoms along the discommensuration lines become mobile due to the strong bond to 4-ATP, while the tendency of the porphyrins towards self-assembly result in a collective motion of gold clusters.

Phthalocyanine-based molecularly imprinted polymers as nucleoside receptors.

A molecularly imprinted polymer (MIP) for tri-O-acetyladenosine (TOAA), PPM(TOAA), was prepared by the combined use of methacrylic acid (MAA) and Zn(II)tetra(4'-methacryloxyphenoxy) phthalocyanine as functional monomers. This MIP exhibited a higher binding ability for TOAA compared to the MIP prepared using only MAA, PM(TOAA), in batch rebinding tests. Scatchard analysis gave a higher association constant of PPM(TOAA) for TOAA (2.

TRMC, XPS, and EPR characterizations of polycrystalline TiO2 porphyrin impregnated powders and their catalytic activity for 4-nitrophenol photodegradation in aqueous suspension.

Characterization of polycrystalline TiO(2) bare or porphyrin impregnated powders, used as photocatalysts for the degradation of 4-nitrophenol (4-NP) in aqueous suspension, was performed by time-resolved microwave conductivity (TRMC) measurements and electronic paramagnetic resonance (EPR) and X-ray photoelectron (XPS) spectroscopies. The presence of porphyrin sensitizers, as the metal-free or Cu [5,10,15,20-tetra (4-tert-butylphenyl)] porphyrin, impregnated onto the TiO(2) surface improved the photocatalytic activity of the bare TiO(2). TRMC measurements indicate that the number and lifetime of the photoinduced excess charge carriers increase in the presence of the macrocycles, and EPR and XPS spectroscopies support the mechanistic hypotheses based on the photoreactivity experiments.

New insights from X-ray photoelectron spectroscopy into the chemistry of covalent enzyme immobilization, with glutamate dehydrogenase (GDH) on silicon dioxide as an example.

A three-step process for immobilization of glutamate dehydrogenase (GDH) on the surface of silicon dioxide has been studied by X-ray photoelectron spectroscopy (XPS). The enzyme layer was deposited on the silicon dioxide surface after first exposing the surface to 3-aminopropyltriethoxysilane (3-APTS) and reacting the silylated surface with glutaraldehyde (GA). Fine XPS analysis, performed after each step of the chemical procedure, revealed unknown details of the step-by-step construction of the enzyme layer under different experimental conditions.

Anthocyanins from bay (Laurus nobilis L.) berries.

Anthocyanin composition in the berries of Laurus nobilis L., a perennial tree or shrub typical of the Mediterranean region, was determined for the first time. The pigments were extracted from the berries with 0.

Identification of anthocyanins in Rhamnus alaternus L. berries.

Anthocyanin composition in berries of Rhamnus alaternus L., a perennial wild shrub typical of the Mediterranean area, was determined for the first time. The pigments were extracted from the berries with 0.

Determination of anthocyanins in Ruscus aculeatus L. berries.

Red berries of Ruscus aculeatus L., a wild shrub typical of Mediterranean Europe and Africa, were investigated for the first time in order to determine the profile of anthocyanins. The pigments were extracted from the skins of the berries with 0.

Highly Chemo- and Regioselective Thiocarbonylation of Conjugated Enynes with Thiols and Carbon Monoxide Catalyzed by Palladium Complexes: An Efficient and Atom-Economical Access to 2-(Phenylthiocarbonyl)-1,3-dienes.

The reaction of 1, 3-conjugated enynes bearing a terminal triple bond with thiols and carbon monoxide in the presence of catalytic quantities of Pd(OAc)(2) (3 mol %) and 1,3-bis(diphenylphosphino)propane (6 mol %) in THF at 110 degrees C gave 2-(phenylthiocarbonyl)-1,3-dienes in moderate to good yields. The thiocarbonylation takes place with high chemo- and regioselectivity, with the attack by the phenylthiocarbonyl group occurring exclusively at carbon-2 of the 1,3-conjugated enyne.

Highly Regioselective Palladium-Catalyzed Thiocarbonylation of Allenes with Thiols and Carbon Monoxide.

A series of mono- and di-substituted allenes underwent direct thiocarbonylation with thiols and carbon monoxide to form the corresponding beta,gamma-unsaturated thioesters in 73-94% yields. This reaction requires catalytic quantities of Pd(OAc)(2) (3 mol %) and triphenylphosphine (12 mol %) in THF under an atmosphere of CO (400 psi) at 100 degrees C for 48 h. Other palladium catalyst systems such as Pd(2)(dba)(3).