Research articles

LepI is an S-adenosylmethionine-dependent pericyclase that catalyses the dehydration, hetero-Diels–Alder reaction and retro-Claisen rearrangement reactions that occur in the formation of the 2-pyridone natural product leporin C. Now, the mechanistic details that underpin this range of catalytic reactions have been uncovered from the crystal structures of LepI and LepI in complex with ligands.

Although methods exist to construct secondary stereocentres containing both a C–F and C–H bond, the ability to form a tertiary C–F bond, remote from pre-existing activating groups, remains challenging. Now, C–F tertiary, benzylic stereocentres have been constructed through a Pd-catalysed enantioselective Heck reaction of acyclic alkenyl fluorides with arylboronic acids.

Active species such as hydrogen and oxygen are commonly introduced into reactors to control the growth of two-dimensional materials. Now, the presence of fluorine—released by the decomposition of a metal fluoride sheet—has also been shown to modulate the growth kinetics of graphene, h-BN and WS₂.

Quantum coherence and dephasing in molecular motions determine the behaviour of many chemical reactions and are the fundamental basis for the concept of coherent control. Now, ultrafast X-ray scattering combined with a detailed structural determination analysis precisely measures the coherent vibrational motions of a polyatomic organic molecule following photoexcitation.

Super-resolution fluorescence microscopy techniques can interrogate entities that fluoresce; however, most chemical or biological processes do not involve fluorescent species. Now, the incorporation of a competitive reaction into a single-molecule fluorescence detection scheme has been shown to enable quantitative super-resolution imaging of non-fluorescent reactions.

A method for engineering chemically modified proteins has now been developed using a chemoenzymatic cascade of sortase-mediated transpeptidation and protein trans-splicing. Using this one-pot approach enabled the generation of site-specifically modified proteins in vitro and in isolated cell nuclei.

The F + para-H₂ → HF + H reaction is an important source of HF in interstellar clouds; however, its unusually high rate and its dynamics at low temperature are not fully understood. Now, quantum-state resolved crossed-beam scattering measurements and anion photoelectron spectroscopy have revealed that this reactivity is caused by a resonance-enhanced tunnelling effect involving a post-barrier resonance state.

Vibrational and translational energies have previously been observed to promote reactions at surfaces occurring via dissociative mechanisms. Now, it has been shown that the reaction of CO₂ with surface-adsorbed atomic hydrogen—which occurs via an associative (Eley–Rideal-type) mechanism—can be driven by vibrationally exciting CO₂.

Abasic sites are amongst the most common forms of DNA damage. Despite their biological significance, little is known regarding the distribution of these sites within DNA. Now a method to sequence abasic sites at single-nucleotide resolution has been developed. This method allows the location of abasic sites to be mapped genome-wide.

Fractal topologies are ubiquitous, and synthetic fractal objects provide unique functional advantages by virtue of their high surface area:volume ratios. Now, a computationally guided bottom-up design approach for constructing protein-based fractal assemblies in response to phosphorylation has been developed. Designed assemblies are shown to perform reversible and efficient molecular capture.

Modulating particular ubiquitin chains using binding molecules is challenging given the diversity of chain lengths and linkages found in vivo. Now, tight binding modulators that are specific to K48-linked ubiquitin chains have been found by combining protein synthesis and screening of macrocyclic peptide ligands.

Non-ribosomal peptide synthetases have now been modified and de novo non-ribosomal peptide synthetases constructed using new assembly points within condensation domains. This approach enabled the production of new-to-nature peptides, including some carrying synthetic amino acids, as well as the generation of peptide libraries.

Conventional chemical reactors are subject to the equilibrium limitations imposed by the overall reaction. It has now been shown that this limitation can be overcome if reactants are fed separately to a reactor and a non-stoichiometric oxygen carrier is used to transfer both oxygen and key chemical information across a reaction cycle.

The relative orientation of molecules when they collide is of particular interest to chemists as it provides information on the preferred collision mechanism. Now, experiments in which NO molecules are oriented sideways to incoming Ar atoms show that the spatial manipulation of the collision partners provides a means to control the scattering outcome.

Natural hydrogenases exclusively utilize Ni and/or Fe to activate or produce hydrogen. Now, a catalytically active [Mn]-hydrogenase has been prepared by incorporating a synthetic Mn complex into the apoenzyme of [Fe]-Hydrogenase. The semi-synthetic [Mn]-hydrogenase shows higher activity than the corresponding Fe analogue.

A set of stereochemically complex and structurally diverse compounds were created from the diterpene natural product pleuromutilin using the complexity-to-diversity strategy. Phenotypic screening identified a compound that induces rapid ferroptotic death of cancer cells. Experiments to probe the mechanism revealed the compound to be an inhibitor of thioredoxin.

Gas sorption studies in porous materials typically reflect their overall gas uptake. Now, using a ‘gas adsorption crystallography’ method, the gas adsorption isotherms of two metal–organic frameworks (MOFs) have been quantitatively decomposed into sub-isotherms that reflect the pore-filling behaviour of various guests in the different types of pores present in the MOFs.

Secondary-sphere interactions serve a fundamental role in controlling the reactivity and selectivity of organometallic and enzyme catalysts, but their study in organocatalytic systems is scarce. Now, it has been shown that the in situ secondary-sphere modification of organocatalysts combined with machine-learning techniques can uncover reaction mechanisms and streamline catalyst optimization.

Structural defects are known to exist in metal–organic frameworks (MOFs), and to affect the materials’ properties, but their exact structures have remained difficult to determine. Now, missing-linker and missing-cluster defects have been observed in a MOF using low-dose transmission electron microscopy, enabling their distributions, evolutions during crystallization and effects on the material’s catalytic activity to be explored.

The reaction between an excited atom and a charged molecule has now been studied at low temperature and a reaction blockading effect has been observed that differs significantly from what is expected from standard chemical capture theory.