J. Appl. Cryst.の発刊に際して

Current status and future perspectives in atom transfer radical polymerization (ATRP) are presented. Special emphasis is placed on mechanistic understanding of ATRP, recent synthetic and process development, and new controlled polymer architectures enabled by ATRP. New hybrid materials based on organic/inorganic systems and natural/synthetic polymers are presented. Some current and forthcoming applications are described.

Atom Transfer Radical Polymerization (ATRP): Current Status and Future Perspectives

This Perspective presents recent advances in macromolecular engineering enabled by ATRP. They include the fundamental mechanistic and synthetic features of ATRP with emphasis on various catalytic/initiation systems that use parts-per-million concentrations of Cu catalysts and can be run in environmentally friendly media, e.g., water. The roles of the major components of ATRP—monomers, initiators, catalysts, and various additives—are explained, and their reactivity and structure are correlated. The effects of media and external stimuli on polymerization rates and control are presented. Some examples of precisely controlled elements of macromolecular architecture, such as chain uniformity, composition, topology, and functionality, are discussed. Syntheses of polymers with complex architecture, various hybrids, and bioconjugates are illustrated. Examples of current and forthcoming applications of ATRP are covered. Future challenges and perspectives for macromolecular engineering by ATRP are discussed.

Macromolecular Engineering by Atom Transfer Radical Polymerization

Mass spectrometry is an essential analytical technique for high-throughput analysis in proteomics and metabolomics. The development of new separation techniques, precise mass analyzers and experimental protocols is a very active field of research. This leads to more complex experimental setups yielding ever increasing amounts of data. Consequently, analysis of the data is currently often the bottleneck for experimental studies. Although software tools for many data analysis tasks are available today, they are often hard to combine with each other or not flexible enough to allow for rapid prototyping of a new analysis workflow. We present OpenMS, a software framework for rapid application development in mass spectrometry. OpenMS has been designed to be portable, easy-to-use and robust while offering a rich functionality ranging from basic data structures to sophisticated algorithms for data analysis. This has already been demonstrated in several studies. OpenMS is available under the Lesser GNU Public License (LGPL) from the project website at http://www.openms.de
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https://link.springer.com/content/pdf/10.1186%2F1471-2105-9-163.pdf

OpenMS – An open-source software framework for mass spectrometry

Electrochemical reduction of an exemplary ATRP catalyst, C 11 Br 2 /Me 6 TREN, is shown to be an efficient process to mediate and execute an ATRP. The onset of polymerization occurs only through passage of a cathodic current achieved under a reductive potential to form Cu 1 Br 2 /Me 6 TREN, within the reaction medium. Unprecedented control over the polymerization kinetics can be attained through electrochemical methods by modulating the magnitude of the applied potential allowing polymerization rate enhancement or retardation. Additional polymerization control is gained through electrochemical “dials” allowing polymerization rate enhancements achieved by larger applied potentials and the ability to successfully switch a polymerization “on” and “off between dormant and active states by application of multistep intermittent potentials.

https://science.sciencemag.org/content/sci/332/6025/81.full.pdf

Electrochemically mediated atom transfer radical polymerization

In the 20 years, since the introduction of electrospray mass spectrometry (ESI-MS), the use of this technique in various fields of inorganic, organometallic, and analytical chemistry has been steadily increasing. In this study, the application of ESI-MS to the study of metal–ligand solution equilibria is reviewed (till 2004 included). In a first section, advantages and drawbacks of ESI-MS in this type of application are described. Subsequently, a list of ca. 300 studies is reported, in which ESI-MS was used to give number and stoichiometry of the species at equilibrium, or also to estimate their stability constants. All studies are classified according to the metal ions under examination. Other related applications, such as host–guest interactions and metal ion-protein binding studies, are briefly reviewed as well. © 2005 Wiley Periodicals, Inc., Mass Spec Rev 25:347–379, 2006

Electrospray mass spectrometry (ESI-MS) in the study of metal-ligand solution equilibria.

Mathematical functions for the representation of chromatographic peaks.

The thermodynamic properties of some copper complexes, among those frequently used as catalysts in controlled/living radical polymerization, has been studied in CH3CN + 0.1 M (C2H5)4NBF4. A combination of different techniques, namely potentiometry, spectrophotometry and cyclic voltammetry, has been used to determine the stability constants of all possible complexes of CuI and CuII present in binary and ternary systems composed of CuI or CuII, a halide ion (X = Cl−, Br−) and a polyamine ligand (L = pentamethyldiethylenetriamine, tris(2-dimethylaminoethyl)amine). The binary Cu−X systems show only mononuclear CuXx complexes, where x = 1, 2, 3, 4 for CuII, and x = 1, 2 for CuI. Conversely, in the case of the binary Cu−L systems, besides the mononuclear complexes CuLl, where l = 1 or 2, also dinuclear complexes Cu2L were found. The ternary systems give rise to a mixture of mononuclear and dinuclear complexes of general formula CumLlXx. Besides the 1:1:1 complex obtained in all combinations, the following speci...

Thermodynamic Properties of Copper Complexes Used as Catalysts in Atom Transfer Radical Polymerization

The present review reports a list of approximately 800 compounds which have been used, tested or proposed for Parkinson’s disease (PD) therapy in the year range 2014–2019 (April): name(s), chemical structure and references are given Among these compounds, approximately 250 have possible or established metal-chelating properties towards Cu(II), Cu(I), Fe(III), Fe(II), Mn(II), and Zn(II), which are considered to be involved in metal dyshomeostasis during PD Speciation information regarding the complexes formed by these ions and the 250 compounds has been collected or, if not experimentally available, has been estimated from similar molecules Stoichiometries and stability constants of the complexes have been reported; values of the cologarithm of the concentration of free metal ion at equilibrium (pM), and of the dissociation constant Kd (both computed at pH = 74 and at total metal and ligand concentrations of 10−6 and 10−5 mol/L, respectively), charge and stoichiometry of the most abundant metal–ligand complexes existing at physiological conditions, have been obtained A rigorous definition of the reported amounts is given, the possible usefulness of this data is described, and the need to characterize the metal–ligand speciation of PD drugs is underlined

https://www.mdpi.com/2218-273X/9/7/269/pdf

Metal Chelation Therapy and Parkinson’s Disease: A Critical Review on the Thermodynamics of Complex Formation between Relevant Metal Ions and Promising or Established Drugs

Colorectal cancer (CRC) is one of the most common tumors in developed countries. The five-year survival rate decreases depending on how advanced the CRC is when first diagnosed. Screening has been proven to greatly reduce mortality from colorectal cancer, but an ideal screening tool is far from being established. Here, we aimed to discover and validate early CRC biomarkers by means of an untargeted/targeted metabolomic approach. A preliminary untargeted analysis of plasma lipids performed on a small patient cohort (30 plasma samples) revealed some alterations that occurred in the presence of this tumor. In particular, medium-chain fatty acids with between six and twelve carbon atoms (C6–C12) were found to be the lipid class that showed the most marked changes upon the development of CRC. In order to evaluate the utility of this lipid class as diagnostic CRC biomarkers, a further study based on a wider cohort of patients (117 plasma samples) was performed. Using a targeted approach, these fatty acids were quantified in plasma samples by means of fast gas chromatography coupled to a time-of-flight analyzer. Plasma samples from patients with CRCs at different tumor stages were analyzed and compared to those from healthy subjects, ulcerative colitis patients, high-grade dysplasia adenoma patients, and breast cancer patients in order to test the specificity and sensitivity of these possible biomarkers. Results revealed significant differences among the considered groups in terms of their C6, C8, C10, and C12 fatty acid plasma concentrations. In particular, receiver operating characteristic (ROC) curves obtained for the C10 fatty acid gave an area under the curve of 0.8195 along with a sensitivity of 87.8 % and a specificity of 80 %, strongly suggesting that it could be a valuable early diagnostic biomarker of CRC.

Valerio Di Marco

Papers

Electrospray mass spectrometry (ESI-MS) in the study of metal-ligand solution equilibria.

Mathematical functions for the representation of chromatographic peaks.

Thermodynamic Properties of Copper Complexes Used as Catalysts in Atom Transfer Radical Polymerization

Metal Chelation Therapy and Parkinson’s Disease: A Critical Review on the Thermodynamics of Complex Formation between Relevant Metal Ions and Promising or Established Drugs

Altered plasma levels of decanoic acid in colorectal cancer as a new diagnostic biomarker