End functionalized polylactides are prepared by ring opening polymerization of L-lactide in the presence of stannous octoate (Sn(Oct)). Three chromophores, 9H-carbazol-ethanol (CA), 9-fluorenyl-methanol (FM), and 2-(4-(2-chloro-4-nitrophenylazo)-N-ethylphenylamino)ethanol (Disperse Red 13, DR), are for the first time used as co-initiators in the polymerization process. The polymerization reaction is initiated by conventional thermal treatment, but in the case of FM, microwave-assisted polymerization is also carried out. CA and FM absorb and emit in the UV portion of the electromagnetic spectrum, whereas DR absorbs in the visible part. The obtained end-capped polylactides derivatives show the same photophysical properties as the initiator, so they are "macromolecular dyes" (MDs) that can be used "as synthesized" or can be blended with commercial poly(lactic acid) (PLA). The blends of PLA with MDs have ultraviolet-visible (UV-Vis) absorption and fluorescence emission features similar to that of MDs and thermal properties typical of PLA. Finally, migration tests, carried out onto the blends of PLA with MDs and PLA with free chromophores, show that MDs are less released than free chromophores both in solution and in the solid phase.
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http://dx.doi.org/10.3390/polym12091979 | DOI Listing |
Commun Biol
January 2025
Institute of Phytopathology, Research Centre for BioSystems, Land Use and Nutrition, Justus Liebig University Giessen, Heinrich-Buff-Ring 26, 35392, Giessen, Germany.
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January 2025
Department of Chemistry, Ball State University, Muncie, IN 47306, USA.
Ipomoeassin F (Ipom-F) is a plant-derived macrocyclic resin glycoside that potently inhibits cancer cell growth through blockage of Sec61-mediated protein translocation at the endoplasmic reticulum. Recently, detailed structural information on how Ipom-F binds to Sec61α was obtained using Cryo-EM, which discovered that polar interactions between asparagine-300 (N300) in Sec61α and four oxygens in Ipom-F are crucial. One of the four oxygens is from the carbonyl group at C-4 of the fatty acid chain.
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January 2025
Centro de Investigação em Química (CIQUP), Institute of Molecular Sciences (IMS), Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal.
An extensive thermochemical study of γ-undecanolactone and δ-undecanolactone has been developed using two complementary calorimetric techniques. The combustion energy of each compound was determined by static-bomb combustion calorimetry, and the corresponding enthalpy of vaporization was determined by high-temperature Calvet microcalorimetry, in which both properties of each compound are reported at = 298.15 K.
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January 2025
Institute of Chemistry and Chemical Technology, Faculty of Natural Sciences and Technology, Riga Technical University, P. Valdena Str. 3, LV-1048 Riga, Latvia.
A metal-free two-step synthetic approach for obtaining indole derivatives from aryl triazole fragment-containing compounds has been developed. In the first step, the Dimroth equilibrium, followed by nitrogen extrusion, Wolff rearrangement, and amine nucleophile addition, leads to the formation of -aryl ethene-1,1-diamines. In the second step, the latter intermediates are cyclized into the target 1-indoles in the presence of iodine.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
Key Laboratory of Enzyme Engineering of Agricultural Microbiology (Ministry of Agriculture), School of Life Sciences, Henan Agricultural University, Zhengzhou, Henan Province, 450046, China.
The antibiotic tetracycline (TC) is an emerging pollutant frequently detected in various environments. Although enzymatic remediation is a promising strategy for mitigating TC contamination, the availability of effective TC-degrading enzymes remains limited, and their mechanisms and applications are not fully understood. This study developed a comprehensive TC-degrading enzyme library from the gut microbiome of the highly TC-resistant saprophagous insect, black soldier fly larvae (BSFL), using an integrated metagenomic and comparative metatranscriptomic approach, identifying 105 potential novel TC-degradation genes.
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