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61.
Edoardo Longo Ksenia Morozova Sine Yener Emanuele Boselli Franco Biasioli Matteo Scampicchio 《Journal of mass spectrometry : JMS》2019,54(5):412-421
This work proposes a novel method for the direct flow injection profiling of acylglycerols in edible oils and fats without preliminary extraction and consequent reconstitution in the injection solvent. The work exploits the outstanding performance of high‐resolution mass spectrometry to target unique elemental compositions even in the most complex matrices. The performance of isopropanol as the unique solvent for both the solubilization and analysis of acylglycerols was investigated in comparison with other classical methods involving preliminary extractions, sample recovery, and analysis. The calibrations of two triglyceride standards (triolein and trilinolenin) were successfully performed in presence and absence of oil matrix. As final application, the effects on the acylglycerol fraction of a heat treatment on three different fat samples (extra virgin olive oil, lard oil, and fat from dry cured ham—speck) were monitored. The proposed method is therefore suitable for a rapid evaluation of acylglycerol fractions in food lipid samples. 相似文献
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Roberta Sinisi Gabriele Candiani Françoise Pecker Matteo Zanda 《Tetrahedron letters》2005,46(38):6515-6518
The racemic α-trifluoromethyl-α-amino-β-sulfone hydroxamates 1 were synthesized by means of a nucleophilic addition of sulfur-stabilized carbanions to a N-Cbz imine of trifluoropyruvate (4). The free amino derivative 1a was the most potent inhibitor of both MMP-3 (stromelysin-1) and MMP-9 (gelatinase-B), showing an IC50 = 14 nM and 1 nM, respectively, and excellent selectivity versus MMP-1 (>5000-fold difference in inhibitory capacity). The N-Me derivative 1b was the most selective for MMP-3 with respect to MMP-9 (62-fold difference). 相似文献
64.
Cocchi M Faeti V Manfredini M Manzini D Marchetti A Sighinolfi S 《Journal of AOAC International》2005,88(2):393-398
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. 相似文献
65.
Simone Madama Ermelinda Falletta Amir Mohammad Malvandi Kevin Arzoni Carlo Brogna Marco Varelli Matteo Bertelli Matteo Conti Martina Larini Federico Guidugli Pietro Traldi Simone Cristoni 《Journal of mass spectrometry : JMS》2022,57(8):e4876
In this work, the isolation step in the linear ion trap was performed using different “q values” conditions at a low collision-induced dissociation (CID) energy leading to the parent ion resolution improvements, reasonably due to better ion energy distribution. According to the results, we obtained a greater resolution and mass accuracy operating in both traditional electrospray and low voltage ionization near the q value = 0.778 and with a CID energy of 10%. This effect was evaluated with low-molecular-mass compounds (skatole and arginine). The proposed optimization yielded a superior instrument performance without adding technological complexity to mass spectrometry analyses. 相似文献
66.
Seyedhosein Payandeh Damian Goonetilleke Matteo Bianchini Jürgen Janek Torsten Brezesinski 《Current Opinion in Electrochemistry》2022
The recent developments in the application of single-crystalline (SC) cathode materials in solid-state batteries are discussed in this mini-review. The characteristics of SC and poly-crystalline (PC) cathode materials are explored, with emphasis on the kinetic and mechanical properties. The critical factors influencing their performance in liquid electrolyte and solid-state battery cells are investigated. Finally, the advantages and disadvantages of both morphologies are discussed and considerations to ensure a fair comparison between SC and PC cathodes in different systems are raised. 相似文献
67.
Poly‐l‐Lactic Acid Nanofiber–Polyamidoamine Hydrogel Composites: Preparation,Properties, and Preliminary Evaluation as Scaffolds for Human Pluripotent Stem Cell Culturing 下载免费PDF全文
Chiara Gualandi Nora Bloise Nicolò Mauro Paolo Ferruti Amedea Manfredi Maurilio Sampaolesi Anna Liguori Romolo Laurita Matteo Gherardi Vittorio Colombo Livia Visai Maria Letizia Focarete Elisabetta Ranucci 《Macromolecular bioscience》2016,16(10):1533-1544
Electrospun poly‐l ‐lactic acid (PLLA) nanofiber mats carrying surface amine groups, previously introduced by nitrogen atmospheric pressure nonequilibrium plasma, are embedded into aqueous solutions of oligomeric acrylamide‐end capped AGMA1, a biocompatible polyamidoamine with arg‐gly‐asp (RGD)‐reminiscent repeating units. The resultant mixture is finally cured giving PLLA‐AGMA1 hydrogel composites that absorb large amounts of water and, in the swollen state, are translucent, soft, and pliable, yet as strong as the parent PLLA mat. They do not split apart from each other when swollen in water and remain highly flexible and resistant, since the hydrogel portion is covalently grafted onto the PLLA nanofibers via the addition reaction of the surface amine groups to a part of the terminal acrylic double bonds of AGMA1 oligomers. Preliminary tested as scaffolds, the composites prove capable of maintaining short‐term undifferentiated cultures of human pluripotent stem cells in feeder‐free conditions.
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69.
Fustero S Chiva G Piera J Volonterio A Zanda M González J Ramallal AM 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(30):8530-8542
Aza-Michael additions of alpha-amino esters to fluorinated acceptors take place in a highly stereoselective manner, to give partially modified Psi[NHCH2]retropeptides incorporating a hydrolytically stable trifluoroalanine mimic. The reaction mechanism has been investigated experimentally and theoretically, in order to explain the effect of the trifluoromethyl group on the reactivity and the origins of the experimentally observed stereocontrol. The reaction is a two-step process, involving a tandem aza-Michael addition followed by a stereoselective hydrogen transfer. Both steps are base-catalyzed. The high level of stereocontrol is the result of a combination of electrostatic interactions and steric effects. 相似文献
70.
Yang Shen Ioanna Kalograiaki Alessio Prunotto Matthew Dunne Samy Boulos Nicholas M. I. Taylor Eric T. Sumrall Marcel R. Eugster Rebecca Martin Alicia Julian-Rodero Benjamin Gerber Petr G. Leiman Margarita Menndez Matteo Dal Peraro Francisco Javier Caada Martin J. Loessner 《Chemical science》2021,12(2):576
Endolysins are bacteriophage-encoded peptidoglycan hydrolases targeting the cell wall of host bacteria via their cell wall-binding domains (CBDs). The molecular basis for selective recognition of surface carbohydrate ligands by CBDs remains elusive. Here, we describe, in atomic detail, the interaction between the Listeria phage endolysin domain CBD500 and its cell wall teichoic acid (WTA) ligands. We show that 3′O-acetylated GlcNAc residues integrated into the WTA polymer chain are the key epitope recognized by a CBD binding cavity located at the interface of tandem copies of beta-barrel, pseudo-symmetric SH3b-like repeats. This cavity consists of multiple aromatic residues making extensive interactions with two GlcNAc acetyl groups via hydrogen bonds and van der Waals contacts, while permitting the docking of the diastereomorphic ligands. Our multidisciplinary approach tackled an extremely challenging protein–glycopolymer complex and delineated a previously unknown recognition mechanism by which a phage endolysin specifically recognizes and targets WTA, suggesting an adaptable model for regulation of endolysin specificity.Combining genetic, biochemical and computational approaches, we elucidated the molecular mechanisms underlying the recognition of Listeria wall teichoic acid by bacteriophage-encoded SH3b repeats. 相似文献