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81.
82.
Joanna Kolniak-Ostek Agnieszka Kita Joanna Miedzianka Lucia Andreu-Coll Pilar Legua Francisca Hernandez 《Molecules (Basel, Switzerland)》2020,25(23)
Opuntia ficus-indica (L.) Mill. is the Cactaceae plant with the greatest economic relevance in the world. It can be used for medicinal purposes, animal nutrition, production of biofuels and phytoremediation of soils. Due to its high content of bioactive compounds, the prickly pear has antioxidant, antimicrobial and anticancer properties. The aim of this study was to determine the polyphenolic, fatty acid and amino acid profile and characterize the antioxidant capacity of seeds of seven Spanish prickly pear cultivars. A total of 21 metabolites, mainly phenolic acids and flavonols, were identified using ultraperformance liquid chromatography photodiode detector quadrupole/time-of-flight mass spectrometry (UPLC-PDA-Q/TOF-MS). Significant differences were found in the phenolic concentrations of the investigated varieties. The highest amount of phenolic compounds (266.67 mg/kg dry matter) were found in the “Nopal espinoso” variety, while the “Fresa” variety was characterized by the lowest content (34.07 mg/kg DM) of these compounds. In vitro antioxidant capacity was positively correlated with the amount of polyphenols. The amino acid composition of protein contained in prickly pear seeds was influenced by the variety. Glutamic acid was the predominant amino acid followed by arginine, aspartic acid and leucine, independent of prickly pear variety. Overall, 13 different fatty acids were identified and assessed in prickly pear seeds. The dominant fatty acid was linoleic acid, with content varying between 57.72% “Nopal ovalado” and 63.11% “Nopal espinoso”. 相似文献
83.
de Araújo Moisés A. Lucas Francisco W. S. Mascaro Lucia H. 《Journal of Solid State Electrochemistry》2020,24(2):389-399
Journal of Solid State Electrochemistry - The present work outlines a simple and novel approach to obtain nanostructured and heterostructured SnS/Sb2S3 thin films. This material showed enhanced... 相似文献
84.
Enrico Luchinat Letizia Barbieri Matteo Cremonini Alessio Nocentini Claudiu T. Supuran Lucia Banci 《Angewandte Chemie (International ed. in English)》2020,59(16):6535-6539
Structure‐based drug development is often hampered by the lack of in vivo activity of promising compounds screened in vitro, due to low membrane permeability or poor intracellular binding selectivity. Herein, we show that ligand screening can be performed in living human cells by “intracellular protein‐observed” NMR spectroscopy, without requiring enzymatic activity measurements or other cellular assays. Quantitative binding information is obtained by fast, inexpensive 1H NMR experiments, providing intracellular dose‐ and time‐dependent ligand binding curves, from which kinetic and thermodynamic parameters linked to cell permeability and binding affinity and selectivity are obtained. The approach was applied to carbonic anhydrase and, in principle, can be extended to any NMR‐observable intracellular target. The results obtained are directly related to the potency of candidate drugs, that is, the required dose. The application of this approach at an early stage of the drug design pipeline could greatly increase the low success rate of modern drug development. 相似文献
85.
Lucia Bartella Leonardo Di Donna Anna Napoli Giovanni Sindona Fabio Mazzotti 《Journal of mass spectrometry : JMS》2020,55(9)
A fast methodology for the assay of parabens in drug and cosmetic preparations has been presented. The procedure developed is based on paper spray tandem mass spectrometry and isotope dilution approach. For each investigated paraben, the corresponding labeled standard has been used in order to improve the accuracy and reproducibility of the analyses. The MS experiments have been performed under MRM conditions, monitoring the transitions [M‐H]? → m/z 92 and [M‐H]? → m/z 98, respectively, for each analyte and the corresponding labeled internal standard. The quantitative assay has been performed using a calibration curve built from 2 to 15 mg/L. The method accuracy, in all case near 100%, was evaluated using fortified samples at two concentration levels, which are representative of the lower and the higher portion of calibration curve. The good values of LOQ, LOD, and reproducibility confirm the consistency of the developed approach. 相似文献
86.
Kathryn A. Dooley Annalisa Chieli Aldo Romani Stijn Legrand Costanza Miliani Koen Janssens John K. Delaney 《Angewandte Chemie (International ed. in English)》2020,59(15):6046-6053
Vincent van Gogh used fugitive red lake pigments that have faded in some paintings. Mapping their distribution is key to understanding how his paintings have changed with time. While red lake pigments can be identified from microsamples, in situ identification and mapping remain challenging. This paper explores the ability of molecular fluorescence imaging spectroscopy to identify and, more importantly, map residual non‐degraded red lakes. The high sensitivity of this method enabled identification of the emission spectra of eosin (tetrabromine fluorescein) lake mixed with lead or zinc white at lower concentrations than elemental X‐ray fluorescence (XRF) spectroscopy used on account of bromine. The molecular fluorescence mapping of residual eosin and two carmine red lakes in van Gogh's The Olive Orchard is demonstrated and compared with XRF imaging spectroscopy. The red lakes are consistent with the composition of paint tubes known to have been used by van Gogh. 相似文献
87.
Ana Barragn Ane Sarasola Lucia Vitali 《Angewandte Chemie (International ed. in English)》2020,59(36):15599-15602
Efficiency in charge‐transport is a fundamental but demanding prerequisite to allow better exploitation of molecular functionalities in organic electronics and energy‐conversion systems. Here, we report on a mechanism that enables a one‐dimensional conductance structure by connecting discrete molecular states at 2.1 eV through the pores of a metal–organic network on Cu(110). Two adjacent, periodic and isoenergetic contributions, namely a molecular resonance and the confined surface‐state, add‐up leading to anisotropic structures, as channels, observable in real‐space conductance images. The adsorption configurations of Br atoms, inorganic byproduct of the redox‐reacted 4,7‐dibromobenzo[c]‐1,2,5‐thiadiazole (2Br‐BTD) molecules on the copper surface, drive the confinement of the Cu surface state within the pores and critically control the channel continuity. Small displacements of the Br atoms change the local surface potential misaligning the energy levels. This work visualizes the effect of order‐disorder transitions caused by the movement of single atoms in the electronic properties of two‐dimensional organic networks. 相似文献
88.
Lucia Veltri Roberta Amuso Raffaella Mancuso Bartolo Gabriele 《Molecules (Basel, Switzerland)》2022,27(1)
In this short review, we highlight the advancements in the field of palladium-catalyzed carbon dioxide utilization for the synthesis of high value added organic molecules. The review is structured on the basis of the kind of substrate undergoing the Pd-catalyzed carboxylation process. Accordingly, after the introductory section, the main sections of the review will illustrate Pd-catalyzed carboxylation of olefinic substrates, acetylenic substrates, and other substrates (aryl halides and triflates). 相似文献
89.
Bramanti E D'Ulivo L Lomonte C Onor M Zamboni R Raspi G D'Ulivo A 《Analytica chimica acta》2006,579(1):38-46
A new procedure is proposed for the sampling and storage of hydrogen sulphide (H2S) and volatile thiols (methanethiol or methyl mercaptan, ethanethiol and propanethiol) for their determination by liquid chromatography. The sampling procedure is based on the trapping/pre-concentration of the analytes in alkaline aqueous solution containing an organic mercurial probe p-hydroxymercurybenzoate, HO-Hg-C6H4-COO− (PHMB), where they are derivatized to stable PHMB complexes based on mercury-sulfur covalent bonds. PHMB complexes are separated on a C18 reverse phase column, allowing their determination by liquid chromatography coupled with sequential non-selective UV-vis (DAD) and mercury specific (chemical vapor generation atomic fluorescence spectrometry, CVGAFS) on-line detectors. PHMB complexes, S(PHMB)2CH3S-PHMB, C2H5S-PHMB and C3H7S-PHMB, are stable alt least for 12 h at room temperature and for 3 months if stored frozen (−20 °C).The best analytical figures of merits in the optimized conditions were obtained by CVGAFS detection, with detection limits (LODc) of 9.7 μg L−1 for H2S, 13.7 μg L−1 for CH3SH, 17.7 μg L−1 for C2H5SH and 21.7 μg L−1 for C3H7SH in the trapping solution in form of RS-PHMB complexes, the relative standard deviation (R.S.D.) ranging between 1.0 and 1.5%, and a linear dynamic range (LDR) between 10 and 9700 μg L−1. Conventional UV absorbance detectors tuned at 254 nm can be employed as well with comparable R.S.D. and LDR, but with LODc one order of magnitude higher than AFS detector and lower specificity. The sampling procedure followed by LC-DAD-CVGAFS analysis has been validated, as example, for H2S determination by a certified gas permeation tube as a source of 3.071 ± 0.154 μg min−1 of H2S, giving a recovery of 99.8 ± 7% and it has been applied to the determination of sulfur compounds in real gas samples (biogas and the air of a plant for fractional distillation of crude oil). 相似文献
90.
A. BallaG. Bencivenni M. CapodiferroS. Cerioni P. CiambroneE. De Lucia G. De RobertisA. Di Domenico D. Domenici J. DongG. Felici M. GattaM. Jacewicz N. LacalamitaS. Lauciani R. LiuzziF. Loddo M. MongelliM. Morello V. PateraA. Pelosi M. PistilliL. Quintieri A. RanieriM. Schioppa E. TshadadzeV. Valentino 《Nuclear Physics B - Proceedings Supplements》2011,215(1):76-78