More Like this

1. Aqueous photo-RAFT polymerization under ambient conditions: synthesis of protein–polymer hybrids in open air

   https://doi.org/10.1039/D4SC01409J  

   Jazani, Arman Moini; Murata, Hironobu; Cvek, Martin; Lewandowska-Andralojc, Anna; Bernat, Roksana; Kapil, Kriti; Hu, Xiaolei; De_Luca_Bossa, Ferdinando; Szczepaniak, Grzegorz; Matyjaszewski, Krzysztof (June 2024, Chemical Science)

   A photoinduced reversible addition-fragmentation chain-transfer (photo-RAFT) polymerization technique in the presence of sodium pyruvate (SP) and pyruvic acid derivatives was developed. 

   more » « less
2. New 1,2,3-Triazoles from (R)-Carvone: Synthesis, DFT Mechanistic Study and In Vitro Cytotoxic Evaluation

   https://doi.org/10.3390/molecules27030769  

   Oubella, Ali; Bimoussa, Abdoullah; N’ait Oussidi, Abdellah; Fawzi, Mourad; Auhmani, Aziz; Morjani, Hamid; Riahi, Abdelkhalek; Esseffar, M’hamed; Parish, Carol; Ait Itto, Moulay Youssef (February 2022, Molecules)

   Aseries of novel 1,4-disubstituted 1,2,3-triazoles were synthesized from an (R)-carvone terminal alkyne derivative via a Cu (I)-catalyzed azide–alkyne cycloaddition reaction using CuSO4,5H2O as the copper (II) source and sodium ascorbate as a reducing agent which reduces Cu (II) into Cu (I). All the newly synthesized 1,2,3-triazoles 9a–h were fully identified on the basis of their HRMS and NMR spectral data and then evaluated for their cell growth inhibition potential by MTS assay against HT-1080 fibrosarcoma, A-549 lung carcinoma, and two breast adenocarcinoma (MCF-7 and MDA-MB-231) cell lines. Compound 9d showed notable cytotoxic effects against the HT-1080 and MCF-7 cells with IC50 values of 25.77 and 27.89 µM, respectively, while compound 9c displayed significant activity against MCF-7 cells with an IC50 value of 25.03 µM. Density functional calculations at the B3LYP/6-31G* level of theory were used to confirm the high reactivity of the terminal alkyne as a dipolarophile. Quantum calculations were also used to investigate the mechanism of both the uncatalyzed and copper (I)-catalyzed azide–alkyne cycloaddition reaction (CuAAC). The catalyzed reaction gives complete regioselectivity via a stepwise mechanism streamlining experimental observations. The calculated free-energy barriers 4.33 kcal/mol and 29.35 kcal/mol for the 1,4- and 1,5-regioisomers, respectively, explain the marked regioselectivity of the CuAAC reaction. 

   more » « less
3. Blue‐light‐induced atom transfer radical polymerization enabled by iron/copper dual catalysis

   https://doi.org/10.1002/pol.20220633  

   Schild, Dirk J.; Bem, Juliana; Szczepaniak, Grzegorz; Jazani, Arman Moini; Matyjaszewski, Krzysztof (December 2022, Journal of Polymer Science)

   Abstract Photoinduced initiators for continuous activator regeneration atom transfer radical polymerization (PICAR ATRP) using sodium pyruvate and blue light (λ_max = 456 nm) is reported. Water‐soluble oligo(ethylene oxide) methyl ether methacrylate (OEOMA₅₀₀) was polymerized under biologically relevant conditions. Polymerizations were conducted with 1000 ppm (with respect to the monomer) concentrations of CuBr₂, tris(2‐pyridylmethyl)amine, and 1000 ppm or less FeCl₃as a cocatalyst in water. Well‐defined polymers with up to 90% monomer conversion, high molecular weights (M_n > 190,000), and low dispersity (1.14 < Ð < 1.19) were synthesized in less than 60 min. The polymerization rate and dispersity were tuned by varying the concentration of sodium pyruvate (SP), iron, and supporting halide, as well as light intensity. The Cu/Fe dual catalysis provided oxygen tolerance enabling rapid, well‐controlled, aqueous PICAR ATRP of OEOMA₅₀₀without deoxygenation. 

   more » « less
4. Sustained bacterial N2O reduction at acidic pH

   https://doi.org/10.1038/s41467-024-48236-x  

   He, Guang; Chen, Gao; Xie, Yongchao; Swift, Cynthia M.; Ramirez, Diana; Cha, Gyuhyon; Konstantinidis, Konstantinos T.; Radosevich, Mark; Löffler, Frank E. (May 2024, Nature Communications)

   Abstract Nitrous oxide (N₂O) is a climate-active gas with emissions predicted to increase due to agricultural intensification. Microbial reduction of N₂O to dinitrogen (N₂) is the major consumption process but microbial N₂O reduction under acidic conditions is considered negligible, albeit strongly acidic soils harbornosZgenes encoding N₂O reductase. Here, we study a co-culture derived from acidic tropical forest soil that reduces N₂O at pH 4.5. The co-culture exhibits bimodal growth with aSerratiasp. fermenting pyruvate followed by hydrogenotrophic N₂O reduction by aDesulfosporosinussp. Integrated omics and physiological characterization revealed interspecies nutritional interactions, with the pyruvate fermentingSerratiasp. supplying amino acids as essential growth factors to the N₂O-reducingDesulfosporosinussp. Thus, we demonstrate growth-linked N₂O reduction between pH 4.5 and 6, highlighting microbial N₂O reduction potential in acidic soils. 

   more » « less
5. Mitigation of copper corrosion in the presence of an organic oxyanion through microstructural optimization

   Acharjee, A; Ghiara, G; Beech, IB; Fields, MW; Amendola, R (December 2025, Corrosion science)

   The investigation aimed to determine whether altering metal microstructure by introducing special grain boundaries through annealing could reduce the corrosion damage observed in the presence of pyruvate. Oxygen-free pure copper coupons were annealed at 325°C, 475°C and 950°C for varying durations to optimize the formation of ∑3 special boundaries. Samples annealed at 475°C for 30 min had the highest yield of such boundaries, thus, were selected for testing. Annealed and as-received, untreated, copper specimens were exposed under stagnant conditions to an aqueous oxic solution of sodium pyruvate for 30 days. Microscopy, spectroscopy, and electrochemical methods were employed to characterize the specimens prior to and following pyruvate exposure. Pyruvate caused localized corrosion of copper seen as micro pitting, irrespective of the specimen treatment. Reduced pitting severity and a decrease in the corrosion rate by 32 % were recorded for annealed coupons when compared to as-received ones. It is proposed that the difference in thickness and morphology of the oxide layer between annealed and as-received coupons, evidenced through electrochemical techniques, is the likely contributor to the improved corrosion resistance of annealed coupons. 

   more » « less