Liquid chromatography/coordination ion spray-mass spectrometry has been used for the identification of reaction products in a model rubber vulcanization process. After LC separation using reversed-phase conditions, AgBF(4) in acetonitrile was added, and strong signals were observed for silica-rubber coupling agents and products of the reaction between these and alkenes. The method performs best for substances containing sulfur chains with chain lengths between two and eight sulfur atoms, but sulfur-free compounds containing triethoxysilyl groups were detected as well. For the latter, the postcolumn addition of NaBF(4) proved to be a suitable alternative. Besides the coupling agents, various reaction products, including sulfur-chain bridged alkenes were identified.
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http://dx.doi.org/10.1021/ac035017p | DOI Listing |
Environ Microbiol Rep
February 2025
Department of Microbiology, University of Helsinki, Helsinki, Finland.
Mycosporine-like amino acids are water-soluble secondary metabolites that protect photosynthetic microorganisms from ultraviolet radiation. Here, we present direct evidence for the production of these compounds in surface scums of cyanobacteria along the Baltic Sea coast. We collected 59 environmental samples from the southern coast of Finland during the summers of 2021 and 2022 and analysed them using high-resolution liquid chromatography-mass spectrometry.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Department of Chemical Engineering, Kwangwoon University, 20, Kwangwoon-ro, Nowon-gu, Seoul 01897, Republic of Korea.
A novel monomer, 9-bis[4-(2-hydroxyethoxy)phenyl]fluorene di(mercaptopropionate), with a highly refractive index, purity, and excellent UV-curable properties, is synthesized through an optimized Fischer esterification process, reacting 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene with 3-mercaptopropionic acid. The structural characterization of this monomer is performed using Fourier-transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, high-performance liquid chromatography, and liquid chromatography-mass spectrometry. The synthesis conditions are optimized using a design-of-experiments approach.
View Article and Find Full Text PDFArch Pharm (Weinheim)
January 2025
Program in Food and Nutrition, Federal University of the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil.
The Amazon rainforest is renowned for its biodiversity and as a reservoir of edible and medicinal plants. The phytochemicals in murici and taperebá fruits serve as natural antioxidants, contributing to cultural preservation, ecosystem protection, and economic opportunities. However, limited scientific research on their composition and health benefits hinders their recognition as functional foods.
View Article and Find Full Text PDFJ Biochem Mol Toxicol
January 2025
Department of Medical Biology, Kocaeli University, Kocaeli, Turkey.
Thymoquinone (TQ) has shown antitumorigenic effects in breast cancer; however, its detailed impact on cell signaling mechanisms requires further investigation. This study aims to elucidate the molecular mechanisms behind TQ's antiproliferative effects in breast cancer by analyzing proteome-level changes. MCF-7 cells were treated with 15 µM TQ, the inhibitory concentration (IC50), for 48 h.
View Article and Find Full Text PDFNeuroscience
January 2025
Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Centre for Preclinical Research and Technology CePT, Banacha 1B, 02-097 Warsaw, Poland.
It is common knowledge that the cerebellum is a structure of the central nervous system that influences the processes of balance and motor coordination. Recently its influence on social interactions has also been emphasized. The sigma receptor agonist: 3-di-o-tolylguanidine (DTG) is characterized by high affinity for sigma 1 and sigma 2 receptors, widely distributed in the cerebellum.
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