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A method has been developed to identify RNA transcript isoforms at the single-molecule level using solid-state nanopore microscopy. In this method, target RNA is refolded into RNA identifiers with designed sets of complementary DNA strands. Each reshaped molecule carries a unique sequence of structural (pseudo)colours that enables identification and quantification using solid-state nanopore microscopy.

The principal mid-visible light-harvesting system in cyanobacteria is the phycobilisome. Now, using broadband multidimensional spectroscopy, delocalized vibronic excitations and sub-picosecond excitation transfer pathways have been observed in the rods of intact phycobilisomes. An observed kinetic bottleneck in the phycobilisome’s core arises from the intramolecular charge-transfer character of the bilin chromophores, enabling photoregulatory processes to operate on the >10-ps timescale.

The total synthesis and complete stereochemical assignment of the cyclic peptide natural product SR-A3—which has potential as a cancer therapeutic—has now been reported. Single-molecule biophysical and cellular experiments reveal a crucial, stereospecific role for a side-chain hydroxyl in SR-A3, which confers enhanced target residence time and efficacy in a mouse tumour model.

Noyori-type hydrogenation catalysts consist of an N–H moiety coordinated to a metal centre. Now, a metal-hydride amidate complex (HMn–NLi) has been isolated and found to have superior reactivity and catalytic performance compared with the corresponding HMn–NH complex, highlighting the superiority of M/NM′ bifunctional catalysis over the classic M/NH bifunctional catalysis for hydrogenation reactions.

The reduction of nitrite (NO₂⁻) to nitric oxide (NO), relevant to the biogeochemical nitrogen cycle as well as radioactive waste, typically occurs at redox-active metal centres. Now, a Lewis acid-capped nitrite has been reduced to the nitrite dianion (NO₂²⁻), a nitrogen-centred radical that connects three redox levels in the global nitrogen cycle through NO₂⁻, NO and N₂O.

In silico chemical prediction of a polyketide synthase gene cluster in the bacterium Gynuella sunshinyii has led to the discovery of a class of natural products called janustatins. The absolute configuration of the stereocentres in these compounds was determined by a combination of techniques including DFT calculations and 2D NMR experiments—and finally confirmed by total synthesis. Janustatins were found to cause delayed, synchronized cell death at subnanomolar concentrations.

Cyclic polymers are topologically interesting and envisioned as a lubricant material, but methods for the scalable synthesis of pure cyclic polymers are currently elusive. Now, a scalable process has been developed by leveraging heterogeneity of the catalysts with the help of compartmentalized custom glassware, namely, a cyclic polymer dispenser.

Oligonucleotide catalysts such as ribozymes and DNAzymes can cleave RNA efficiently and specifically but are typically dependent on high concentrations of divalent cations, limiting their biological applications. A modular XNAzyme catalyst composed of 2′-deoxy-2′-fluoro-β-d-arabino nucleic acid (FANA) has now been developed that can cleave long (>5 kb), highly structured mRNAs under physiological conditions and enables allele-specific catalytic RNA knockdown inside cells.

Amines with free N–H groups have long posed a tremendous challenge in transition metal-catalysed amination reactions. Now, use of a bidentate phosphorus ligand enables the palladium-catalysed oxidative amination of simple olefins with Lewis basic amines, with no prefunctionalization, forming both alkyl and aryl allylamines.

The study of rare isotopes is hampered by their scarcity, cost and sometimes toxicity. Now polyoxometalate ligands have been shown to facilitate the capture of f-block elements and their characterization. Single-crystal X-ray diffraction structures have been obtained for several molecular complexes, including three of the rare curium-248, from minute amounts (micrograms) of material.

Given the importance of amine compounds, methods for their synthesis continue to be in high demand. Now, a palladium-catalysed strategy has been developed for the selective oxidative amination of unactivated olefins with Lewis basic amines, via C(sp³)–H activation, forming architecturally versatile and functionally diverse allylamines in a single step.

In some cases, hydrogen adsorption close to its boiling temperature shows unusually high monolayer capacities, but the microscopic nature of this adsorbate phase is not well understood. Now, H₂ adsorbed on a well-ordered mesoporous silica surface has been shown to form a 2D monolayer with very short H₂···H₂ intermolecular distances and a density more than twice that of bulk-solid H_2.

The application of machine learning to big data, to make quantitative predictions about reaction outcomes, has been fraught with failure. This is because so many chemical-reaction data are not fit for purpose, but predictions would be less error-prone if synthetic chemists changed their reaction design and reporting practices.

A grand challenge for bio-based plastics is the ability to cost-effectively manufacture high-performance polymers directly from renewable resources that are also recyclable-by-design. A one-step conversion of xylose to polyesters has been reported, combining a sustainable lifecycle with impressive materials performance.

An alcohol-functionalized cyclophane has been shown to form a bowl-shaped cavity large enough to host tris(bipyridine)ruthenium(ii). The macrocycle captures, and suppresses the activity of, the ruthenium complex in water but, when oxidized to its ketone-bearing counterpart, releases the ruthenium guest.

Supramolecular catalysis can emulate many features of enzymatic transformations. Now, a complex proton wire mechanism — enabling the dual activation of a nucleophile and an electrophile through reciprocal proton transfer — has been shown to operate during the β-glycosylation of sugars within a self-assembled capsule.

Lukas Veth and Paweł Dydio discuss the importance of ligands in transition metal catalysis, looking at the success story of xantphos and why it should earn the title of ‘privileged ligand’.

The biosynthesis of fuscimiditide, a ribosomally synthesized post-translationally modified peptide, has now been reported. Heterologous expression and analysis of fuscimiditide showed it contained two side-chain–side-chain ester linkages and an aspartimide in its backbone. The aspartimide moiety is unexpectedly stable, suggesting this structure is the intended natural product.