Recent Advancements in the LC- and GC-Based Analysis of Malondialdehyde (MDA): A Brief Overview

Malondialdehyde (MDA) is an end-product of lipid peroxidation and a side product of thromboxane A(2) synthesis. Moreover, it is not only a frequently measured biomarker of oxidative stress, but its high reactivity and toxicity underline the fact that this molecule is more than "just" a biomarker. Additionally, MDA was proven to be a mutagenic substance. Having said this, it is evident that there is a major interest in the highly selective and sensitive analysis of this molecule in various matrices. In this review, we will provide a brief overview of the most recent developments and techniques for the liquid chromatography (LC) and gas chromatography (GC)-based analysis of MDA in different matrices. While the 2-thiobarbituric acid assay still is the most prominent methodology for determining MDA, several advanced techniques have evolved, including GC-MS(MS), LC-MS(MS) as well as several derivatization-based strategies.     

Advancements in Gold-Catalyzed Cascade Reactions to Access Carbocycles and Heterocycles: An Overview

This review summarizes recent developments (from 2006 to 2022) in numerous important and efficient carbo- and heterocycle generations using gold-catalyzed cascade protocols. Herein, methodologies involve selectivity, cost-effectiveness, and ease of product formation being controlled by the ligand as well as the counter anion, catalyst, substrate, and reaction conditions. Gold-catalyzed cascade reactions covered different strategies through the compilation of various approaches such as cyclization, hydroarylation, intermolecular and intramolecular cascade reactions, etc. This entitled reaction is also useful for the synthesis of spiro, fused, bridged carbo- and heterocycles.     

Recent Advancements in Natural Plant Colorants Used for Hair Dye Applications: A Review

There is an on-going demand in recent years for safer and “greener” hair coloring agents with the global consumer awareness of the adverse effects of synthetic hair dyes. The belief in sustainability and health benefits has focused the attention of the scientific community towards natural colorants that serve to replace their synthetic toxic counterparts. This review article encompasses the historical applications of a vast array of natural plant hair dyes and summarizes the possible coloration mechanisms (direct dyeing and mordant dyeing). Current information on phytochemicals (quinones, tannins, flavonoids, indigo, curcuminoids and carotenoids) used for hair dyeing are summarized, including their botanical sources, color chemistry and biological/toxicological activities. A particular focus is given on research into new natural hair dye sources along with eco-friendly, robust and cost-effective technologies for their processing and applications, such as the synthetic biology approach for colorant production, encapsulation techniques for stabilization and the development of inorganic nanocarriers. In addition, innovative in vitro approaches for the toxicological assessments of natural hair dye cosmetics are highlighted.     

Erratum to: Recent Advances in Asymmetric Nitroso Diels-Alder Reactions

Russian Journal of Organic Chemistry - The second author should be Chen-Fu Liu.     

Recent Advancements in the Development of Anti-Breast Cancer Synthetic Small Molecules

Among all cancer types, breast cancer (BC) still stands as one of the most serious diseases responsible for a large number of cancer-associated deaths among women worldwide, and diagnosed cases are increasing year by year worldwide. For a very long time, hormonal therapy, surgery, chemotherapy, and radiotherapy were used for breast cancer treatment. However, these treatment approaches are becoming progressively futile because of multidrug resistance and serious side effects. Consequently, there is a pressing demand to develop more efficient and safer agents that can fight breast cancer belligerence and inhibit cancer cell proliferation, invasion and metastasis. Currently, there is an avalanche of newly designed and synthesized molecular entities targeting multiple types of breast cancer. This review highlights several important synthesized compounds with promising anti-BC activity that are categorized according to their chemical structures.     

Analysis of the carcinogen 4,4′-methylenedianiline (MDA) in gamma-ray and in autoclave-sterilized polyurethane

Summary A carcinogen, 4,4-methylenedianiline (MDA, p,p-diaminodiphenylmethane), was determined in gammaray- and in autoclave-sterilized thermoplastic polyurethane (PU). The determination of MDA in aqueous extracts of PU has been reported, however recovery of MDA and its determination using a complete dissolution of PU by organic solvents have not. In addition, we report the MDA determination in methanol extract of PU. No MDA was detected in gamma-ray sterilized thermoplastic PU, but in autoclavesterilized thermoplastic PU, MDA was detected (possibly formed by hydrolysis). The amount of MDA formed was inversely related to the molecular weight of PU by a second order equation. No change in the weight average molecular weight was observed as a result of autoclave sterilization. Essentially the same amounts of MDA were extracted from PU with serum as with methanol.

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Analyse des Carcinogens 4,4-Methylendianilin (MDA) in -Strahlen- und Autoklav-sterilisiertem Polyurethan

     

Fouling Mitigation by Surface-Patterned Polymeric Membranes in Water Treatment: A Review of Recent Advancements in Fabrication Techniques

The world is constantly challenged regarding managing environmental and ecological contamination due to human and industrial activities. This is because of the constant threat posed by pollution. Nowadays, membrane-based technology is a growing field, making practically all the separation of foulant from wastewater possible. The membrane fouling resulting from the interaction between the foulant and the membrane surface presents a challenge for the technology in maintaining performance over extended periods of operation. As a result, there is a rising interest in research focusing mainly on creating patterned membrane surfaces that reduce fouling and effectively enhance the surface area. This article comprehensively overviews the most recent and cutting-edge techniques that can be applied to modify and construct high-performance patterned membranes suitable for ultrafiltration, microfiltration, nanofiltration, and reverse osmosis (UF, MF, NF, and RO) water purification processes. In this study, recent developments in membrane material are dissected, focusing on methods for improving surface chemistry, structure, and hydrodynamics, as well as the consequences of these characteristics on filtering performance.     

Ab initio Study of the Geometrical and Electronic Structures of Sc(MDA)2 and Sc(MDA)3 Molecules

The geometrical parameters, force fields, and vibrational spectra of various geometrical configurations of Sc(MDA)₂ and Sc(MDA)₃ molecules were calculated using the restricted Hartree—Fock method taking into account electron correlation by second–order Möller–Plesset perturbation theory. The calculations were performed using effective pseudopotentials for describing atomic cores and valence double zeta basis sets supplemented by polarization functions. It was shown that the configurations of D ₃ [Sc(MDA)₃] and D _2h [Sc(MDA)₂] symmetry correspond to the minimum on the potential energy surface of the ground electronic state. The configurations of D _3h symmetry for Sc(MDA)₃ and D _2d for Sc(MDA)₂ correspond to first–order saddle points. The ground electronic states of Sc(MDA)₂ and Sc(MDA)₃ molecules are the states of ² A _g and ¹ A ₁ symmetries, respectively. For both configurations (D _2h and D _2d of the Sc(MDA)₂ molecule, the energies of vertical electron transitions were calculated using the CASSCF method. The formation of chemical bonding in the compounds considered was analyzed. It was shown that the Sc–O bond is predominantly ionic and the conjugation is characteristic only of the oxygen–carbon skeleton of the chelate fragment. The results obtained are compared with literature experimental and theoretical data for related compounds.     

化学元素的发现和名称便览(续)

以原子序数为序,列表介绍化学元素的发现和名称由来,包括超重元素至118号。     

异卟啉研究进展

异卟啉是通过改变卟啉大环结构而得到的卟啉类似物。由于具有独特的结构和性能,如阴离子识别、稳定异常价态金属离子、Mbius芳香性、构建新型超分子体系、电子转移以及近红外荧光等特性,异卟啉已引起人们越来越多的兴趣。本文简要介绍了异卟啉研究的意义,异卟啉的命名以及分类,并重点介绍了N-错位卟啉、扩展卟啉和氧化卟啉原等异卟啉的研究现状及最新进展。同时对咔咯、氧化咔咯原、卟啉烯、核修饰卟啉、亚卟啉和杯吡咯等异卟啉的发展现状及其性能作了简要概述。通过对异卟啉化合物研究,可得到很多普通卟啉难以实现的性能,并有望在相关领域获得实际应用。本文在介绍异卟啉研究的同时,还尝试翻译了一些相关专业术语。     

Analysis of multiblock datasets using ComDim: Overview and extension to the analysis of (K + 1) datasets

ComDim analysis was designed to assess the relationships between individuals and variables within a multiblock setting where several variables, organized in blocks, are measured on the same individuals. An overview of this method is presented together with some of its properties. Furthermore, we discuss a new extension of the method of analysis to the case of (K+1) datasets. More precisely, the aim is to explore the relationships between a response dataset and K other datasets. An illustration of this latter strategy of analysis on the basis of a case study involving Time Domain ‐ Nuclear Magnetic Resonance data is outlined and the outcomes are compared with those of Multiblock Partial Least Squares regression.     

Cyclotriphosphate: A Brief History,Recent Developments,and Perspectives in Synthesis

There has been a recent upsurge in the study and application of approaches utilizing cyclotriphosphate 1 (cyclo-TP, also known as trimetaphosphate, TMP) and/or proceeding through its analogues in synthetic chemistry to access modified oligo- and polyphosphates. This is especially useful in the area of chemical nucleotide synthesis, but by no means restricted to it. Enabled by new high yielding and easy-to-implement methodologies, these approaches promise to open up an area of research that has previously been underappreciated. Additionally, refinements of concepts of prebiotic phosphorylation chemistry have been disclosed that ultimately rely on cyclo-TP 1 as a precursor, placing it as a potentially central compound in the emergence of life. Given the importance of such concepts for our understanding of prebiotic chemistry in combination with the need to readily access modified polyphosphates for structural and biological studies, this paper will discuss selected recent developments in the field of cyclo-TP chemistry, briefly touch on ultraphosphate chemistry, and highlight areas in which further developments can be expected.     

Erratum to: Recent Advances in C-O Bond Construction via C-H Activation

Russian Journal of Organic Chemistry - The second author should be Chen-Fu Liu.     

The Acidity of Malondialdehyde and the Stability of its Complexes with Nickel(II) and Copper(II)

The acidity of malondialdehyde as well as the stability of its 1 :1-complexes with Ni^II and Cu^II have been determined (Table). In comparison with the enolates of aliphatic β-dike-tones the anion C₃H₃O₂? has not only a strikingly reduced basicity, but is also a grossly inferior ligand for metal cations.     

Unlocking Hydrogenation for C-C Bond Formation: A Brief Overview of Enantioselective Methods

Hydrogenation of π-unsaturated reactants in the presence of carbonyl compounds or imines promotes reductive C-C coupling, providing a byproduct-free alternative to stoichiometric organometallic reagents in an ever-increasing range of C=X (X = O, NR) additions. Under transfer hydrogenation conditions, hydrogen exchange between alcohols and π-unsaturated reactants triggers generation of electrophile-nucleophile pairs, enabling carbonyl addition directly from the alcohol oxidation level, bypassing discrete alcohol oxidation and generation of stoichiometric byproducts.