Celebrating Women in Chemistry

This International Women’s Day, the editors of Communications Chemistry reflect on the responsibilities that journal editors have towards promoting gender equity in STEM, and outline some of the ways in which editors can show up for women in chemistry.

Efforts are ongoing to address inequities in scientific fields. Here, the author provides a critical look at the practice and culture of science with calls to action to broaden participation and recognition of talented members from marginalized groups in the chemical sciences.

Dr Zoe Schnepp and Professor David Smith share their experiences of working part-time in academia, discussing some of the benefits and challenges, and offering advice to those who may be seeking to work part-time.

Polly Arnold is a Professor of chemistry at the University of California, Berkeley and Director of the Chemical Sciences Division at Lawrence Berkeley National Laboratory in the US. Polly’s research focuses on exploratory synthetic chemistry. Such knowledge underpins the discovery of catalysts and our understanding of the behavior of nuclear waste.

Dr Camille Bishop is an incoming Assistant Professor in the Department of Chemical Engineering and Materials Science at Wayne State University. She obtained her PhD in chemistry at the University of Wisconsin—Madison, where she prepared glasses with liquid crystal-like packing using physical vapor deposition, after obtaining her B.S. in chemistry from the University of Chicago.

Nancy Scott Burke Williams is an Associate Professor of Chemistry at the Keck Science Department of Claremont McKenna, Pitzer, and Scripps Colleges in Claremont, California, where she has been in the faculty since 2003. She was born in Puyallup, WA to Burke and Nancy Williams, from whom she takes most of her names.

Hear from Professor Nathalie Katsonis on her academic journey and passions, her thoughts on the future directions of chemical research, and her experience of being an Editorial Board Member for Communications Chemistry.

Professor Kristin Wustholz answers questions on her scientific career, scientific developments she is excited about and directions the spectroscopy and photochemistry communities should focus on, as well as her experience of being an Editorial Board Member for Communications Chemistry.

In celebration of International Women’s Day, on 6 March 2020 the University of Nottingham hosted its second Women in Chemistry conference. Or, as branded by a security guard at the host building, a ‘chemical ladies’ meeting’. Victoria Richards recounts the event and shares key take-home messages from the speakers.

Monitoring glycosylation is a key quality control for protein therapeutics, however, most established methods such as hydrophilic interaction chromatography with fluorescence detection (HILIC-Fld) and liquid chromatography-mass spectrometry (LC-MS) require time-consuming procedures and complicated data analysis. Here, the authors apply high performance anion exchange chromatography coupled to pulsed amperometric detection (HPAEC-PAD) for the batch-to-batch monitoring of glycans on complex antigens with a simplified procedure.

PUFA-plasmalogens show neuroprotective properties via the stimulation of CREB activation, however, their efficiency is limited by low bioavailabilities. Here, the authors develop PUFA-plasmalogen-loaded liquid crystalline lipid-peptide nanoparticles to achieve sustained CREB activation in an in vitro neurodegeneration model.

Supersaturated amorphous drug–salt–polymer systems are known to improve the aqueous solubility of poorly water-soluble drugs as well as their bioavailability, however, the rational optimization of such systems is largely unexplored. Here, the authors optimize the polymer and salt combination for the drug celecoxib and achieve improved biopharmaceutical performance by experimental and computational characterization of their amorphous solid dispersions.

Functionalized nanocellulose is a promising drug carrier, however, studying surface functionalization at the atomic scale remains challenging due to spectroscopic methodology limitations. Here, the authors use dynamic nuclear polarization enhanced ¹³C and ¹⁵N solid-state NMR to optimize the drug loading on nanocellulose using aqueous heterogeneous chemistry.

Hydrogels exhibit advantageous biocompatibility as carriers of chemotherapeutic agents, and those composed of natural polymers such as chitosan additionally offer biodegradability, environmental benefits, and low cost. Here, the authors develop highly swellable bio-hydrogels consisting of chitosan-graft-glycerol and carboxymethyl chitosan-graft-glycerol for sustained and pH-controlled anticancer vincristine sulfate release.

Pyrroles are an important scaffold in medicinal chemistry with various bioactivities; however, the selective chemical halogenation of pyrroles remains challenging. Here, the authors develop an enzymatic site-selective chlorination of pyrrolic heterocycles by a flavin-dependent halogenase PrnC and apply it to the chemoenzymatic synthesis of a chlorinated analogue of the fungicide Fludioxonil.

β-Amino acid-containing macrolactams are a known natural product family exhibiting structural and functional diversity, however, the natural chemical space of this family remains underexplored. Here, the authors use a targeted β-amino acid-specific homology-based multi-query search to identify their potential microbial producers, explore the variation of their biosynthetic gene clusters, heterologously produce ciromicin A, and identify new macrotermycin derivatives.

Microbial enzymes are capable of degrading certain synthetic polymers, with most polyethylene terephthalate (PET) degrading enzymes known to derive from bacteria or fungi. Here, the authors describe an archaeal originating feruloyl-esterase PET46 enzyme with a flexible lid domain and PET degradation capability.

Phthalate acid ester hydrolases are of promise for the microbial degradation of phthalate acid ester plasticizers, however, only a small number of PAE hydrolases have been characterized. Here, the authors report the structural and functional characterization of MehpH, a monoalkyl phthalate (MBP) hydrolase that degrades MBP to phthalic acid and butanol.

Angucyclines are a class of natural products that harbor unusual structural rearrangements through B- or C-ring cleavage of their tetracyclic backbone, however, the enzymes leading to C-ring cleavage remain poorly understood. Here, the authors use targeted gene deletion and complementation as well as metabolomics to study the function of putative oxygenases involved in lugdunomycin biosynthesis, and reveal their potential roles towards C-ring cleavage.

3-Deoxy-D-arabino-heptulosonate-7-phosphate synthase (DAHPS) is a key enzyme in the shikimate pathway for the biosynthesis of aromatic compounds, however, its activity is inhibited by L-Phe and L-Tyr. Here, the authors report the D154N point mutation of yeast DAHPS, which retains the wild type enzyme activity but relieves the inhibition by L-Phe, thus increasing the production of downstream aromatic amino acid derivatives.

Berberine is a plant-derived benzylisoquinoline alkaloid with diverse pharmaceutical activities, however, the production of berberine from medicinal plants and organic synthesis remains unsustainable. Here, the authors report the complete biosynthesis of berberine in yeast by engineering genes from plants and bacteria.

Protein tyrosine kinase Src is known to phosphorylate Ras protein on tyrosine32 and 64, and uncouple Ras from the signaling cascade, however, the mechanisms through which phosphorylation modulates these interactions remain poorly understood. Here, the authors quantify the major mono-phosphorylation level on tyrosine64 by ³¹P NMR and mutagenesis, and reveal the key conformational changes of phosphorylated Ras using BeF₃⁻ complexes by X-ray crystallography and ¹⁹F NMR, providing new mechanistic and conformational insights into Ras dynamics regulation.

PAPP-A and PAPP-A2 are two isoforms of pregnancy-associated plasma protein A that cleave insulin-like growth factor binding proteins (IGFBPs) to modulate insulin-like growth factor signaling, however the structure and function of PAPP-A2 remain underexplored. Here, the authors report the cryo-EM structure of PAPP-A2, computational modeling of the PAPP-A2/IGFBP5 complex, and biochemical studies that reveal unique structural features and a lower IGFBP5 cleaving efficiency compared with PAPP-A.

Capsid proteins (CPs) of various icosahedral and rod-shaped viruses exhibit structural diversity and tunability as well as application in smart hybrid nanoparticles, however, the potential of CPs of filamentous plant viruses remains underexplored. Here, the authors exploit the structure-based design of CP from potato virus Y to tune the shape, size, RNA encapsidation ability, symmetry, stability, and surface functionalization of nanoparticles.

Tryptophan is often found on the surface of membrane-associated proteins that interact with the lipid membrane, however, the exact role of each tryptophan residue remains unknown. Here, the authors use racemic protein crystallography to probe dedicated tryptophan interactions of a model bacteriocin aureocin A53 with tetrahedral anions mimicking the head group of phospholipids.

Etrumadenant has been developed as a dual-acting adenosine A_2A/A_2B receptor antagonist, and is now in clinical trials for the treatment of cancer, however, the exact drug–receptor binding mode is unknown. Here, the authors determine the high-resolution co-crystal structure of Etrumadenant with a thermostabilized A_2AAR construct and reveal the interaction of its cyano group with T88^3.36.

Fission yeast Schizosaccharomyces pombe shares many characteristics with higher eukaryotes. Here, the authors investigate the structure and function of respiratory complex IV from S. pombe, reveal the subunit arrangements and the reaction sequence of O₂ reduction.

Blue copper proteins serve as models for understanding how proteins tune metal binding properties, however, the mechanism through which they do so remains unclear. Here, the authors investigate carbon-deuterium bond vibrations in Nostocplastocyanin to study key copper-ligand interactions in different redox states, and reveal specific impacts of perturbation to the cupredoxin scaffold on copper coordination and the redox properties of plastocyanin.

Excavatolide B (excB) is a marine briarane type diterpenoid with anti-inflammatory properties, however, its cellular targets and mode-of-action remain unknown. Here, the authors develop two covalent probes of excB and apply them through a chemoproteomics approach to identify STING as a direct target of excB in living mammalian cells.

mRNA display strategies such as random non-standard peptide integrated discovery (RaPID) system allow screening of large peptide libraries to identify reversible binding to a target of interest. Here, the authors develop a covalent version of this methodology, photocrosslinking-RaPID, allowing identification of peptides that efficiently covalently modify their target of choice via photoaffinity labelling.

Gadolinium-based contrast agents are the gold standard for magnetic resonance imaging (MRI), however, their poor stability causes safety problems in clinical applications. Here, the authors develop two chiral Gd(III) DOTA-based complexes with a macrocyclic backbone that show higher relaxivities and stabilities than benchmark complexes.

Various fatty acids and aldehydes can be synthesized from acetylene and carbon monoxide by nickel sulfide catalysts under volcanic hydrothermal conditions compatible with aqueous early earth conditions, however, their chemical complexity remains underexplored. Here, the authors use ¹³C-labelling together with untargeted ultrahigh-resolution mass spectrometry to categorize carboxylic acid functional groups, revealing C2-addition driven compound diversity as well as new sulfur containing classes.

Macrotermitine termites farm fungi as a food source in the genus Termitomyces, but the biochemical mechanisms underlying this symbiotic relationship are largely unknown. Here, the volatile organic compound repertoire of Termitomyces from Macrotermes natalensis colonies is explored in order to deduce fungal signals and ecological patterns relating to the stability of this relationship.

Deep learning-based in silico retrosynthesis prediction methods are able to accelerate retrosynthetic planning, however, their prediction performance remains limited. Here, the authors develop a semi-template-based deep generative model, G²Retro, that can better predict the reactants for one-step retrosyntheses.

Isotope ratios of mollusk shell carbonates are commonly used to reconstruct past environmental conditions, but the shell organic matrix is often overlooked. Here, the authors find the hydrogen and oxygen isotope compositions of the organic matrix of modern Mytilus galloprovincialis shells from sites along a coast-to-upper-estuary environmental gradient reflect environmental variables.

Artificial photosynthesis aims to produce fuels and chemicals from simple, abundant building blocks, such as water and carbon dioxide, with sunlight as a source of energy. Here, the authors review recent developments in biomimetic, compartmentalized vesicular systems towards artificial photosynthesis, and highlight challenges and opportunities in mimicking this complex natural reaction system.

The simultaneous electroreduction of carbon dioxide and nitrate is a promising and environmentally benign route to urea production, but achieving high selectivity for urea electrosynthesis via this route remains challenging. Here, CuO_xZnO_y electrodes are shown to enable the efficient and selective production of urea under mild conditions, with the efficiency found to strongly depend on the metal ratio within the catalyst composition.

Room-temperature ionic liquids are increasingly investigated as electrolytes for electrocatalytic CO₂ reduction thanks to their high intrinsic ionic conductivities, wide electrochemical potential windows, and high CO₂ absorption capacities and solubilities. Here, seven imidazolium-based ionic liquids are investigated as electrolytes for the electrochemical conversion of CO₂ to CO using a silver foil cathode, with their stability, co-catalytic effects, and varying selectivities elucidated.

Conversion of methane to methanol via methanol derivatives such as methyl bisulfate (MBS) allows to achieve high selectivity and yield, but separating MBS from oxidizing agents such as sulfuric acid is an energy-intense step. Here, the authors eliminate the need for separation of MBS from sulfuric acid by replacing the former with methyl trifluoroacetate, which is subsequently hydrolyzed into high-purity methanol.

Platinum dispersed on metal oxide supports is widely used for industrially important catalysis such as the reverse water gas shift reaction, but active site migration and subsequent alterations in catalytic performance are still not fully understood. Here, the use of platinum on ceria nanodomes shows the detrimental effect of migration of platinum nanoparticles to titania supports at elevated temperatures.

Single-atom catalysts (SACs) are highly promising materials for applications such as electrocatalytic water splitting, but coordination geometries around catalyst centers remain the subject of debate. Here, the authors use spin-polarized ab initio molecular dynamics simulations to compare the aqueous reactivities of iron porphyrin and iron pyridine SACs embedded in graphene, and predict the interfacial water dissociative adsorption mechanism under a moderate electric field for an iron porphyrin SAC.

Single atom catalysts dispersed on a surface demonstrate great promise for a variety of catalytic reactions, but their aggregation leads to a degradation of catalytic activity. Here, the authors use quantum mechanical calculations to study the catalytic activity of Cu adatoms stabilized with N-heterocyclic carbenes (NHCs) on a Cu(100) surface, finding that NHC-decoration significantly reduces the energy barriers to electrocatalytic CO hydrogenation and C–C coupling.

Understanding the atomic dynamics of active catalyst sites is crucial for the precise optimization of catalyst performance. Here, the authors employ operando XAFS and DRIFTS to study the dynamics of the mobility of platinum and copper dopants in bimetallic and trimetallic gold nanoclusters supported on ceria, using the water-gas shift process as a model reaction.

Metal nanoclusters have shown great promise as electrochemiluminescence (ECL) luminophores, but understanding the relationship between ECL and atomic structure is highly challenging. Here, the ECL of nanocluster isomers Au₂₀(SAdm)₁₂(CHT)₄ and Au₂₀(TBBT)₁₆ is studied, giving insight into structure–property relationships.

Understanding the formation pathways of multimetallic clusters is essential to the progress of cluster research, but remains highly challenging. Here, time-dependent crystallization, mass spectrometry, and quantum chemical calculations are used to gain insight into the formation pathways of bismuth–tungsten carbonyl clusters.

Constructing crystalline materials with specific stimuli-responsive dynamics and controlled molecular motion affords opportunities for innovative functionality and applications. Here, the authors discuss recent developments in dynamic solid-state framework materials across a range of material classes, exploring key phenomena associated with such complex dynamics.

CHA zeolites display high selectivity toward CO₂ adsorption, but the influence of the nature and concentration of their extra-framework cations on the formation of silanol sites, and the respective impact on CO₂ sorption, is poorly understood. Here, the authors use high-resolution solid-state magic-angle spinning ¹H NMR and Fourier-transform infrared spectroscopy to study the effects of post-synthetic exchange of extra-framework alkali-metal cations on silanol sites in nanosized CHA zeolites.

Crystals that undergo mechanical motion in response to light are of great interest for the development of photoactuating smart materials, but their disintegration hinders the characterization of accompanying structural changes. Here, two iso-structural photoreactive metal-organic crystals are found to undergo [2 + 2] cycloaddition under UV light in a single-crystal-to-single-crystal manner, enabling detailed characterization of their photomechanical behaviours.

Gas chromatography is a useful tool to identify and characterize wines, usually by selecting some compounds for a particular classification problem, yet, with limited success. Here, the authors decode the estates perfectly and age 50% correctly of twelve red Bordeaux wines from unrestricted, raw gas chromatograms using machine learning.

The collagen present in rare prehistoric bones allows for their age to be estimated by radiocarbon dating, but this method is destructive towards these precious archaeological remains. Here, the authors report a non-destructive method based on near-infrared hyperspectral imaging to precisely localize the collagen preserved in parts of ancient specimens suitable for radiocarbon dating.

NMR relaxometry can provide information on paramagnetic as well as diamagnetic compounds in solution by analyzing nuclear-spin relaxation times, and, operated at ultra-low magnetic fields, slow processes can be studied. Here, the authors employ zero and ultra-low magnetic fields using an atomic magnetometer as a simple, portable, robust, inexpensive, and sensitive tool to analyze chemical solutions and biofluids.

Zero- and ultralow-field (ZULF) nuclear magnetic resonance (NMR) has emerged as a complementary technique to conventional high-field (≳1 T) NMR, however, the ability to distinguish heteronuclear coupling remains challenging due to the low abundance of certain nuclei. Here, the authors apply non-hydrogenative parahydrogen-induced hyperpolarization to identify naturally abundant molecules, and demonstrate the detection of pyridine derivatives at a concentration level of ~1 mM.

Ozone-induced dissociation (OzID) coupled with ion mobility spectrometry-mass spectrometry (IMS-MS) provides the capacity for in-depth structural elucidation of lipids with isomer separation and confident assignment of double bond positions, however, OzID data analysis remains very challenging. Here, the authors develop a Python tool, LipidOz, for the automated determination of lipid double bond locations from complex LC-OzID-IMS-MS data, with a combination of traditional automation and deep learning approaches.

The collision cross section (CCS) values derived from ion mobility spectrometry (IMS) are a significant molecular property used for compound identification, however, accurate CCS prediction from molecular structure remains challenging. Here, the authors develop an accurate SigmaCCS approach based on graph neural networks using 3D conformers generated from SMILES strings to directly predict CCS values from molecular structures.

Identification of chemical compounds, present in a sample, is a fundamental task of chemical analysis, but matching obtained spectra with chemical databases is limited to identifying known molecules. Here, the authors report a deep learning architecture for recommending molecular structures, including those of novel molecules, given sample mass spectra alone.

Infrared spectroscopy is widely used for detailed insights into the three-dimensional molecular structure of biomolecules, however, the accurate description of experimental data by theoretical approaches remains challenging due to the dynamic processes that occur in biomolecules. Here, the authors report the accurate interpretation and reproduction of experimental infrared spectra of a model peptide in the gas phase using a combination of replica-exchange molecular dynamics simulations, machine learning and ab initio calculations based on representative structural conformers.

Heterogeneous reaction of NO₂ with atmospheric humic like substances is a potentially important source of volatile organic compounds, but the role of ubiquitous water-soluble aerosol components in this chemistry remains largely unexplored. Here, secondary electrospray ionization ultrahigh-resolution mass spectrometry is used to obtain real-time measurements of VOCs formed during the heterogeneous reaction of gas phase NO₂ and a solution containing gallic acid as a model for moderately acidic aerosol particles.

Ozonolysis of isoprene is considered to be an important source of atmospheric formic acid, but its underlying reaction mechanisms are poorly understood. Here, the authors study the reaction of the primary isoprene ozonolysis products formaldehyde oxide and formaldehyde and evaluate atmospheric implications using a global chemistry-transport model.

Polycyclic aromatic hydrocarbons (PAHs) are the main precursors to soot particles in combustion systems, but the transition from gas-phase species to organic soot clusters is still not fully understood. Here, the authors study infant soot particles with mass spectrometry and kinetic Monte Carlo simulations and identify peri-condensed PAHs to be the most thermodynamically stable species.

Attosecond science is nowadays a well-established research field, and table-top attosecond sources based on high-harmonic generation are routinely used to access electronic motion in matter at its natural time scale. Here, the authors describe a new way of doing chemistry—attochemistry—by directly acting on the electronic motion, and discuss a few key open questions in this emerging field.

Controlling excited-state reactivity is a long-standing challenge in photochemistry, as desired pathways may be inaccessible or compete with unwanted channels, which is problematic for applications. Here, the authors show that 2,3,5-trifluorination on the phenolate ring of the green fluorescent protein chromophore leads to both pathway selectivity and doubles the photoisomerization quantum yield.

Single-molecule fluorescent probes can be used for nanoreporting, localization, and now multiplexing, but understanding their stochastic fluctuations in emission intensity is crucial for accurate signal interpretation. Here, the authors elucidate the blinking dynamics of rhodamine, BODIPY, and antraquinone dyes, demonstrate that multiplexing performance improves with photophysical differences, and suggest guidelines for the selection and design of organic fluorophores for single-molecule multiplexing.

Single-walled carbon nanotubes are a promising material for optical applications, but large band gap modulations remain challenging to realize. Here, the authors functionalize single-walled carbon nanotubes using 1,4-diiodooctafluorobutane, achieving a shift in the material’s photoluminescence to wavelengths of 1320 nm.

Metal–organic frameworks functionalized with photoresponsive molecules are of interest as materials with photoswitchable electronic properties, but designing such MOFs remains challenging. Here, the authors use in silico molecular design to explore photoswitchable MOF candidates that incorporate spiropyran photoswitches at controlled positions and with defined intermolecular distances and orientations.

Computational methods enable the rapid evaluation of the gas uptake capabilities of metal–organic frameworks. Here, MOFs are screened for their CO₂ capture abilities using machine learning trained on molecular simulation data, with new effective point charge descriptors introduced to aid this process.

Understanding adsorption reactions at solid–water interfaces is key to enabling important chemical separations; however, when such surfaces are confined in nanopores, nanoconfinement effects on surface chemistry are difficult to predict. Here, X-ray absorption fine structure spectroscopy and operando flow microcalorimetry are used to determine the effects of nanoconfinement on the energetics and coordination environments of trivalent lanthanides adsorbed on alumina surfaces within nanopores.

Mineral precipitation in porous media is relevant for various energy-related applications such as oil extraction, geothermal systems, or nuclear waste disposal, but crystallization retardation as a function of pore size and shape is poorly explored. Here, the authors study barite crystallization in micro-confinement, showing that retardation of crystallization can start in pores of less than 1 µm in size, with the probability of nucleation scaling with pore volume.