2025: Stone 2025 | School of Chemistry | University of Bristol

bristol.ac.uk

A Solvent Selection Framework for Porous Organic Polymers

Selecting suitable solvents to control the morphology and properties of novel functional materials remains a significant challenge, especially when there is limited or no prior knowledge of the material and its solubility. In this work, we present a solvent selection toolkit for functional porous organic polymers. We have developed the MLoc algorithm for the fast determination of Hansen solubility parameters (HSPs) for novel materials. This approach requires ultraviolet and visible (UV/vis) absorbance data, measured for a number of candidate solvents using a standard laboratory setup. Based on these measurements, MLoc determines the HSPs for novel porous organic materials using a centroid-location algorithm based on Hansen distance. The results of this algorithm can guide the fine-tuning of both morphology and carbon-capture performance of target polymers, which we illustrate in a case study. In this example, performing the polymer synthesis in solvents with HSPs most similar to the porous material has led to CO2 uptake improved by 220% compared to a reported analogue (from 2.16 to 6.95 wt %). Using MLoc, we have also compiled a HSP database for 17 porous organic polymers, enhanced with data for over 80 reactions, sampling different conditions, which we present as a resource for future data-driven research in this area.

pubs.acs.org

All Roads Lead to Carbinolamine: QM/MM Study of Enzymatic C–N Bond Cleavage in Anaerobic Glycyl Radical Enzyme Choline Trimethylamine-Lyase (CutC)

The anaerobic glycyl radical enzyme choline trimethylamine-lyase (CutC) is produced by multiple bacterial species in the human gut microbiome and catalyzes the conversion of choline to trimethylamine (TMA) and acetaldehyde. CutC has emerged as a promising therapeutic target due to its role in producing TMA, which is subsequently oxidized in the liver to form trimethylamine-N-oxide (TMAO). Elevated TMAO levels are associated with several human diseases, including atherosclerosis and other cardiovascular disorders─a leading cause of mortality worldwide. Understanding the catalytic mechanism of this enzyme should aid successful design of potent inhibitors. Here, we employed extensive molecular dynamics (MD) simulations to reveal that hydrogen bonding within the CutC active site plays a crucial role in orienting choline for the initial pro-S hydrogen abstraction, leading to the formation of the α-hydroxy radical. The reaction mechanism was explored with quantum mechanics/molecular mechanics (QM/MM). The performance of three density functionals (B3LYP-D3, ωB97X-D3, and M06–2X) was tested against DLPNO–CCSD(T) ab initio calculations. These results indicate that choline cleavage occurs via TMA migration leading to a stable product carbinolamine which likely undergoes 1,2-elimination to acetaldehyde and TMA in water. Mechanistic insights consistently support the TMA migration pathway over direct TMA elimination, providing clear evidence for the preferred reaction mechanism. Two distinct mechanistic pathways were identified: one with a relatively high activation energy barrier, and the other with a lower barrier which is in a good agreement with the previously reported experimental kinetic parameters. QM/MM MD simulations further confirm that Glu491 functions as a catalytic base, abstracting a proton from the α-hydroxy radical and thereby facilitating the experimentally observed C–N bond cleavage. The relative binding affinity of the reactant (choline) and product (carbinolamine) was estimated with alchemical relative binding free energy calculations, complemented by noncovalent interaction analysis. These results elucidate the molecular basis for differences in their interactions with CutC (particularly highlighting key electrostatic interactions with Asp216 and Glu491) providing insights for future inhibitor design.

pubs.acs.org

http://www.rsc.org/events/detail/82458/stone-symposium

t.co

Lecturer in Computational Chemistry and Scientific Computing at University of Bristol

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Lecturer in Computational Chemistry and Scientific Computing at University of Bristol

Discover an exciting academic career path as a Lecturer in Computational Chemistry and Scientific Computing at jobs.ac.uk. Don't miss out on this job opportunity - apply today!

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The America I loved is gone

It was a nation of dreams, built for the screen. Then it shattered

theguardian.com

Pharmaceutical Tariffs: The What and the How

science.org

Canada goose fights off bald eagle in rare, symbolism-laden battle on ice

Photographer captures 20-minute clash between birds emblematic of Canada and US amid high trade tensions

theguardian.com

Nessa Carson on LinkedIn: Chemistry Data Summer Internship

Are you, or do you know, a passionate chemistry or chemical engineering undergraduate in the UK looking for a non-lab-based summer internship (aimed at 3rd…

linkedin.com