The synthesis of methyl 2-(benzyloxycarbonyl)amino-3-dimethylaminopropenoate. The synthesis of trisubstituted pyrroles, 3-amino-2H-pyran-2-ones,fused 2H-pyran-2-ones and 4H-pyridin-4-ones

Methyl 2-(benzyloxycarbonyl)aimno-3-dimemylaminopropenoate ( 2 ) was prepared from methyl N-(benzyloxycarbonyl)glycinate ( 1 ) and t-butoxybis(dimethylamino)methane, and used as a reagent for preparation of substituted 3-(benzyloxycarbonyl)amino-4H-quinolizin-4-ones 5 and 6 , ?2H-pyran-2-ones 17–19 , ?2H-1-benzopyran-2-ones 28–31 , and -naphthopyrans 32–35 , ?2H-pyrano[3,2-c]pyridine-2,5-dione 46 , -pyrano-[4,3-b]pyran-2,5-dione 47 , -pyrano[3,2-c]benzopyran-2,5-dione 48 , -pyrano[2,3-c]pyrazol-6-ones 49 and 50 , -pyrano[2,3-d]pyrirnidin-7-ones 51 and 52 derivatives. In the reaction of 2 with 1,3-diketones trisubsti tuted pyrroles 14–16 were formed. Selective removal of benzyloxycarbonyl group was achieved by cat alytic transfer hydrogenation with Pd/C in the presence of cyclohexene to afford free 3-amino compounds 7 , 8 , 20 , 36–38 and 53–57 in yields better than 80%.     

Determination of metal concentration in fat supplements for swine nutrition by atomic absorption spectroscopy

The presence of some essential and toxic metals in fat supplements for swine diet was investigated. Collected samples represented a relevant production of the Italian industry. In particular, some samples were enriched with antioxidants or waste cooking oils. The method for the determination of Ca, Cu, Cd, Fe, Mg, Mn, Ni, Pb, and Zn in fat samples was developed by means of a certified reference material (CRM 186) and a representative fatty sample (RFS). All samples were digested in closed vessels in a microwave oven and then analyzed by flame atomic absorption or graphite furnace atomic absorption spectrometry. The entire analytical method provided a satisfactory repeatability and reproducibility confirmed by agreement between the experimental recovery data obtained for the CRM 186 sample and, with the method of standard additions, for the RFS material. The samples generally showed a small amount of metals compared with the recommended daily intake for the essential elements. On the other hand, some samples contained a significant concentration, from an analytical point of view, of Cd, Ni, and Pb. Principal component analysis (PCA) was applied to inspect the experimental data obtained from samples analysis. Basically no differences were detected in terms of metal concentration among the fat supplements analyzed.     

Os(bpy)2(CO)(enIA)][OTf]2: a novel sulfhydryl-specific metal-ligand complex

The synthesis and physical-chemical characterization of the metal-ligand complex [Os(bpy)2(CO)(enIA)][OTf]2 (where enIA = ethylenediamine iodoacetamide) with a sulfhydryl-specific functional group is described. The UV and visible absorption and luminescence emission, including lifetime and steady-state anisotropy, are reported for the free probe and the probe covalently linked to two test proteins. The spectroscopic properties of the probe are unaffected by chemical modification and subsequent covalent linkage to the proteins. The luminescence lifetime in aqueous buffer is approximately 200 ns and the limiting anisotropy is greater than 0.125, suggesting a potentially useful probe for biophysical investigations.     

Anisotropic metal nanoparticles: Synthesis, assembly, and optical applications

This feature article highlights work from the authors' laboratories on the synthesis, assembly, reactivity, and optical applications of metallic nanoparticles of nonspherical shape, especially nanorods. The synthesis is a seed-mediated growth procedure, in which metal salts are reduced initially with a strong reducing agent, in water, to produce approximately 4 nm seed particles. Subsequent reduction of more metal salt with a weak reducing agent, in the presence of structure-directing additives, leads to the controlled formation of nanorods of specified aspect ratio and can also yield other shapes of nanoparticles (stars, tetrapods, blocks, cubes, etc.). Variations in reaction conditions and crystallographic analysis of gold nanorods have led to insight into the growth mechanism of these materials. Assembly of nanorods can be driven by simple evaporation from solution or by rational design with molecular-scale connectors. Short nanorods appear to be more chemically reactive than long nanorods. Finally, optical applications in sensing and imaging, which take advantage of the visible light absorption and scattering properties of the nanorods, are discussed.     

Highly Sensitive “Off/On” EPR Probes to Monitor Enzymatic Activity

The assessment of unregulated level of enzyme activity is a crucial parameter for early diagnoses in a wide range of pathologies. In this study, we propose the use of electron paramagnetic resonance (EPR) as an easy method to probe carboxylesterase (CE) enzymatic activity in vitro. For this application, were synthesized two amphiphilic, nitroxide containing esters, namely Tempo-C12 (T-C12) and Tempo-2-C12 (T-2-C12). They exhibit low solubility in water and form stable micelles in which the radicals are EPR almost silent, but the hydrolysis of the ester bond yields narrows and intense EPR signals. The intensity of the EPR signals is proportional to the enzymatic activity. CEs1, CEs2 and esterase from porcine liver (PLE) were investigated. The obtained results show that T-C12 and T-2-C12-containing systems display a much higher selectivity toward the CEs2, with a Limit of Detection of the same order of those ones obtained with optical methods.     

Analysis of Fatty Acids,Amino Acids and Volatile Profile of Apple By-Products by Gas Chromatography-Mass Spectrometry

Apple industrial by-products are a promising source of bioactive compounds with direct implications on human health. The main goal of the present work was to characterize the Jonathan and Golden Delicious by-products from their fatty acid, amino acid, and volatile aroma compounds’ point of view. GC-MS (gas chromatography-mass spectrometry) and ITEX/GC-MS methods were used for the by-products characterization. Linoleic and oleic were the main fatty acids identified in all samples, while palmitic and stearic acid were the representant of saturated ones. With respect to amino acids, from the essential group, isoleucine was the majority compound identified in JS (Jonathan skin) and GS (Golden skin) samples, lysine was the representant of JP (Jonathan pomace), and valine was mainly identified in GP (Golden pomace). A total number of 47 aroma volatile compounds were quantified in all samples, from which the esters groups ranged from 41.55–53.29%, aldehydes 29.75–43.99%, alcohols from 4.15 to 6.37%, ketones 4.14–5.72%, and the terpenes and terpenoids group reached values between 2.27% and 4.61%. Moreover, the by-products were valorized in biscuits manufacturing, highlighting their importance in enhancing the volatile aroma compounds, color, and sensorial analysis of the final baked goods.     

Thermo-physical properties measurements of hygroscopic and reactive material (zeolite 13X) for open adsorptive heat storage operation

Journal of Thermal Analysis and Calorimetry - The determination of the thermo-physical properties (density, specific heat capacity, and thermal conductivity) of hygroscopic and reactive solid...     

Alkyl 2-(2-benzoyl-2-ethoxycarbonyl-1-ethenyl)amino-3-dimethylaminopropenoates in the synthesis of heterocyclic systems

Alkyl 2-(2-benzoyl-2-ethoxycarbonyl-1-ethenyl)amino-3-dimethylaminopropenoates 4a,b were prepared. They react with C-nucleophiles such a 2-pyridinylacetonitrile 5 and methyl-2-quinolinylacetate 8, cyclohexane-1,3-dione 10 and its derivatives 12 and 14, resorcinol derivative 16 , 2-naphtol 18, 2-pyranone derivatives 20 and 22, and 4-hydroxypyridin-2(1H)-one 24, to form substituted amino derivatives of quinolizine 6, benzo[c]quinolizine 9, tetrahydrobenzopyran-2-one 11, 13, 15 , naphto[2,1-b]pyran-3-one 19 , pyranopyranones 21, 23, and pyrano[3,2-c]pyridine 25.     

Volatiles and Antifungal-Antibacterial-Antiviral Activity of South African Salvia spp. Essential Oils Cultivated in Uniform Conditions

Spontaneous emissions of S. dentata Aiton and S. scabra Thunb., as well as the essential oil (EO) composition of the cited species, together with S. aurea L., were investigated. The chemical profile of the first two species is reported here for the first time. Moreover, in vitro tests were performed to evaluate the antifungal activity of these EOs on Trichophyton mentagrophytes, Microsporum canis, Aspergillus flavus, Aspergillus niger, and Fusarium solani. Secondly, the EO antibacterial activity against Escherichia coli, Staphylococcus aureus, and Staphylococcus pseudointermedius was examined, and their antiviral efficacy against the H1N1 influenza virus was assessed. Leaf volatile organic compounds (VOCs), as well as the EOs obtained from the arial part of Salvia scabra, were characterized by a high percentage of sesquiterpene hydrocarbons (97.8% and 76.6%, respectively), mostly represented by an equal amount of germacrene D (32.8% and 32.7%, respectively). Both leaf and flower spontaneous emissions of S. dentata, as well as the EO composition, showed a prevalence of monoterpenes divided into a more or less equal amount of hydrocarbon and oxygenated compounds. Interestingly, its EO had a non-negligible percentage of oxygenated sesquiterpenes (29.5%). S. aurea EO, on the contrary, was rich in sesquiterpenes, both hydrocarbons and oxygenated compounds (41.5% and 33.5%, respectively). S. dentata EO showed good efficacy (Minimal Inhibitory Concentration (MIC): 0.5%) against M. canis. The tested EOs were not active against E. coli and S. aureus, whereas a low inhibition of S. dentata EO was observed on S. pseudointermedius (MIC = 10%). Once again, S. dentata EO showed a very good H1N1 inhibition; contrariwise, S. aurea EO was completely inactive against this virus. The low quantity of S. scabra EO made it impossible to test its biological activity. S. dentata EO exhibited interesting new perspectives for medicinal and industrial uses.