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1. CMR Exploration. I. Filament Structure with Synthetic Observations

   https://doi.org/10.3847/1538-4365/acbfb0  

   Kong, Shuo; Ossenkopf-Okada, Volker; Arce, Héctor G.; Klessen, Ralf S.; Xu, Duo (April 2023, The Astrophysical Journal Supplement Series)

   Abstract In this paper, we carry out a pilot parameter exploration for the collision-induced magnetic reconnection (CMR) mechanism that forms filamentary molecular clouds. Following Kong et al., we utilize Athena++ to model CMR in the context of resistive magnetohydrodynamics (MHD), considering the effect from seven physical conditions, including the ohmic resistivity ( η ), the magnetic field ( B ), the cloud density ( ρ ), the cloud radius R , the isothermal temperature T , the collision velocity v x , and the shear velocity v z . Compared to their fiducial model, we consider a higher and a lower value for each one of the seven parameters. We quantify the exploration results with five metrics, including the density probability distribution function ( ρ -PDF), the filament morphology (250 μ m dust emission), the B – ρ relation, the dominant fiber width, and the ringiness that describes the significance of the ringlike substructures. The exploration forms straight and curved CMR filaments with rich substructures that are highly variable in space and time. The variation translates to fluctuation in all five metrics, reflecting the chaotic nature of magnetic reconnection in CMR. A temporary B ∝ ρ relation is noticeable during the first 0.6 Myr. Overall, the exploration provides useful initial insights into the CMR mechanism. 

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2. Recent Advances and Future Perspectives of Synthetic Polypeptides from N -Carboxyanhydrides

   https://doi.org/10.1021/acs.macromol.9b01450  

   Song, Ziyuan; Tan, Zhengzhong; Cheng, Jianjun (November 2019, Macromolecules)
3. Synthetic Simplification of Carolacton Enables Chemical Genetic Studies in Streptococcus mutans

   https://doi.org/10.1021/acsinfecdis.9b00213  

   Solinski, Amy E.; Scharnow, Amber M.; Fraboni, Americo J.; Wuest, William M. (May 2019, ACS Infectious Diseases)
4. Synthetic Mimics of Native Siderophores Disrupt Iron Trafficking in Acinetobacter baumannii

   https://doi.org/10.1021/acsinfecdis.1c00119  

   Bohac, Tabbetha J.; Fang, Luting; Banas, Victoria S.; Giblin, Daryl E.; Wencewicz, Timothy A. (August 2021, ACS Infectious Diseases)
5. Mono ‐ and Bis ‐Alkylated Lumazine Sensitizers: Synthetic, Molecular Orbital Theory, Nucleophilic Index and Photochemical Studies

   https://doi.org/10.1111/php.13310  

   Sosa, María José; Urrutia, María Noel; Schilardi, Patricia L.; Quindt, Matías I.; Bonesi, Sergio M.; Denburg, Dobrushe; Vignoni, Mariana; Greer, Alexander; Greer, Edyta M.; Thomas, Andrés H. (August 2020, Photochemistry and Photobiology)

   Abstract Mono‐ andbis‐decylated lumazines have been synthesized and characterized. Namely,mono‐decyl chain [1‐decylpteridine‐2,4(1,3H)‐dione]6aandbis‐decyl chain [1,3‐didecylpteridine‐2,4(1,3H)‐dione]7aconjugates were synthesized by nucleophilic substitution (S_N2) reactions of lumazine with 1‐iododecane inN,N‐dimethylformamide (DMF) solvent. Decyl chain coupling occurred at theN¹site and then theN³site in a sequential manner, without DMF condensation. Molecular orbital (MO) calculations show ap‐orbital atN¹but notN³, which along with a nucleophilicity parameter (N) analysis predict alkylation atN¹in lumazine. Only after the alkylation atN¹in6a, does ap‐orbital onN³emerge thereby reacting with a second equivalent of 1‐iododecane to reach the dialkylated product7a. Data from NMR (¹H,¹³C, HSQC, HMBC), HPLC, TLC, UV‐vis, fluorescence and density functional theory (DFT) provide evidence for the existence ofmono‐decyl chain6aandbis‐decyl chain7a. These results differ to pterinO‐alkylations (kinetic control), whereN‐alkylation of lumazine is preferred and then to dialkylation (thermodynamic control), with an avoidance of DMF solvent condensation. These findings add to the list of alkylation strategies for increasing sensitizer lipophilicity for use in photodynamic therapy. 

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