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A major antimicrobial resistance mechanism in Gram-negative bacteria is the production of β-lactamase enzymes. The increasing emergence of β-lactamase-producing multi-drug-resistant “superbugs” has resulted in increases in costly hospital Emergency Department (ED) visits and hospitalizations due to the requirement for parenteral antibiotic therapy for infections caused by these difficult-to-treat bacteria. To address the lack of outpatient treatment, we initiated an iterative program combining medicinal chemistry, biochemical testing, microbiological profiling, and evaluation of oral pharmacokinetics. Lead optimization focusing on multiple smaller, more lipophilic active compounds, followed by an exploration of oral bioavailability of a variety of their respective prodrugs, provided 36 (VNRX-7145/VNRX-5236 etzadroxil), the prodrug of the boronic acid-containing β-lactamase inhibitor 5 (VNRX-5236). In vitro and in vivo studies demonstrated that 5 restored the activity of the oral cephalosporin antibiotic ceftibuten against Enterobacterales expressing Ambler class A extended-spectrum β-lactamases, class A carbapenemases, class C cephalosporinases, and class D oxacillinases.

Renewable 3-allyl-5-vinylveratrole (AVV) has been evaluated and classified as a biobased cross-linkable vinyl monomer in free-radical chain polymerization. AVV can be readily synthesized in four st...

Utility of the pyridazine motif is growing in popularity as pharmaceutical and agrochemical agents. The detection and structural characterisation of such materials is therefore imperative for the successful development of new products. Signal amplification by reversible exchange (SABRE) offers a route to dramatically improve the sensitivity of magnetic resonance methods, and we apply it here to the rapid and cost‐effective hyperpolarisation of substituted pyridazines. The 33 substrates investigated cover a range of steric and electronic properties and their capacity to perform highly effective SABRE is assessed. We find the method to be tolerant to a broad range of electron donating and withdrawing groups; however, good sensitivity is evident when steric bulk is added to the 3‐ and 6‐positions of the pyridazine ring. We optimise the method by reference to a disubstituted ester that yields signal gains of >9000‐fold at 9.4 T (>28% spin polarisation)., SABRE enables pyridazines to be detected by 1H NMR with greater than 28% polarisation.

Gold-catalyzed hydroarylation of unactivated alkynes with indoles have previously been reported to proceed with double indole addition to produce symmetrical bis(indolyl)methanes (BIMs). We demonstrate for the first time that the selectivity of the gold-catalyzed reaction can be fully switched to allow for isolation of the vinylindole products instead. Furthermore, this selective reaction can be utilized to synthesize the more difficult to access unsymmetrical BIMs from readily available starting materials.

Recent drug recalls (e.g., valsartan and ranitidine) linked to the discovery of nitrosamine impurities have led to increased regulatory scrutiny in the manufacturing process of marketed medicines, ...

The recent discovery of nitrosamines within marketed drugs, such as Valsartan, has led to changes within the regulatory landscape. Most notably, the requirement for a risk evaluation of the presenc...

The canonical mechanistic model explaining potassium channel gating is of a conformational change that alternately dilates and constricts a collar-like intracellular entrance to the pore. It is based on the premise that K+ ions maintain a complete hydration shell while passing between the transmembrane cavity and cytosol, which must be accommodated. To put the canonical model to the test, we locked the conformation of a Kir K+ channel to prevent widening of the narrow collar. Unexpectedly, conduction was unimpaired in the locked channels. In parallel, we employed all-atom molecular dynamics to simulate K+ ions moving along the conduction pathway between the lower cavity and cytosol. During simulations, the constriction did not significantly widen. Instead, transient loss of some water molecules facilitated K+ permeation through the collar. The low free energy barrier to partial dehydration in the absence of conformational change indicates Kir channels are not gated by the canonical mechanism., The transition between conducting and non-conducting states of K+ channels has been explained by conformational changes at the intracellular entrance to the conduction pathway. Here authors demonstrate that control over K+ currents in Kir channels is not explained by the canonical pore-gating model, as conduction is not impaired by a constricted inner helix bundle.

Androgenetic alopecia (AGA) and acne vulgaris are two conditions commonly seen by dermatologists. Androgens and the androgen receptors play an essential role in the manifestation of both conditions, and some systemic therapies function by interfering in this pathway. The use of topical antiandrogen therapies has gained traction in recent years due to their potential efficacy in treating AGA and acne vulgaris, as well as their reduced adverse effects compared with systemic drugs. This review discusses the role of androgens in skin physiology and pathology and assesses the potential efficacy and safety of three topical antiandrogen therapies in the treatment of AGA and acne vulgaris. A literature review utilizing the PubMed, US Clinical Trials, and SCOPUS databases was conducted to search for randomized clinical trials, systematic reviews, cohort studies, case reports, and other relevant published studies on the pathogenesis and treatment of each condition with topical finasteride, ketoconazole shampoo, and cortexolone 17α-propionate (C17P). The results demonstrated that topical formulations of finasteride, ketoconazole, and C17P are promising treatments for male pattern hair loss, especially topical finasteride in combination with topical minoxidil. Limited studies have shown C17P to have potential in treating acne vulgaris in both males and females. Minimal adverse effects have been reported in clinical trials for all topical therapies, although topical finasteride is still contraindicated in pregnancy. Recognizing the preliminary evidence, more peer-reviewed studies on topical antiandrogen treatments for AGA and acne vulgaris are necessary before definitive recommendations can be made regarding efficacy and safety. There is also a critical need to include more women in study populations for these treatments.

Contains fulltext : 245512.pdf (Publisher’s version ) (Open Access) Patients with Hirschsprung disease (HSCR) do not always receive a genetic diagnosis after routine screening in clinical practice. One of the reasons for this could be that the causal mutation is not present in the cell types that are usually tested-whole blood, dermal fibroblasts or saliva-but is only in the affected tissue. Such mutations are called somatic, and can occur in a given cell at any stage of development after conception. They will then be present in all subsequent daughter cells. Here, we investigated the presence of somatic mutations in HSCR patients. For this, whole-exome sequencing and copy number analysis were performed in DNA isolated from purified enteric neural crest cells (ENCCs) and blood or fibroblasts of the same patient. Variants identified were subsequently validated by Sanger sequencing. Several somatic variants were identified in all patients, but causative mutations for HSCR were not specifically identified in the ENCCs of these patients. Larger copy number variants were also not found to be specific to ENCCs. Therefore, we believe that somatic mutations are unlikely to be identified, if causative for HSCR. Here, we postulate various modes of development following the occurrence of a somatic mutation, to describe the challenges in detecting such mutations, and hypothesize how somatic mutations may contribute to 'missing heritability' in developmental defects.

There is an urgent need for oral agents to combat resistant Gram-negative pathogens. Here, we describe the characterization of VNRX-5236, a broad-spectrum boronic acid β-lactamase inhibitor (BLI), and its orally bioavailable etzadroxil prodrug, VNRX-7145. VNRX-7145 is being developed in combination with ceftibuten, an oral cephalosporin, to combat strains of Enterobacterales expressing extended-spectrum β-lactamases (ESBLs) and serine carbapenemases. VNRX-5236 is a reversible covalent inhibitor of serine β-lactamases, with inactivation efficiencies on the order of 104 M-1 · sec-1, and prolonged active site residence times (t1/2, 5 to 46 min). The spectrum of inhibition includes Ambler class A ESBLs, class C cephalosporinases, and class A and D carbapenemases (KPC and OXA-48, respectively). Rescue of ceftibuten by VNRX-5236 (fixed at 4 μg/ml) in isogenic strains of Escherichia coli expressing class A, C, or D β-lactamases demonstrated an expanded spectrum of activity relative to oral comparators, including investigational penems, sulopenem, and tebipenem. VNRX-5236 rescued ceftibuten activity in clinical isolates of Enterobacterales expressing ESBLs (MIC90, 0.25 μg/ml), KPCs (MIC90, 1 μg/ml), class C cephalosporinases (MIC90, 1 μg/ml), and OXA-48-type carbapenemases (MIC90, 1 μg/ml). Frequency of resistance studies demonstrated a low propensity for recovery of resistant variants at 4× the MIC of the ceftibuten/VNRX-5236 combination. In vivo, whereas ceftibuten alone was ineffective (50% effective dose [ED50], >128 mg/kg), ceftibuten/VNRX-7145 administered orally protected mice from lethal septicemia caused by Klebsiella pneumoniae producing KPC carbapenemase (ED50, 12.9 mg/kg). The data demonstrate potent, broad-spectrum rescue of ceftibuten activity by VNRX-5236 in clinical isolates of cephalosporin-resistant and carbapenem-resistant Enterobacterales.

A major resistance mechanism in Gram-negative bacteria is the production of β-lactamase enzymes. Originally recognized for their ability to hydrolyze penicillins, emergent β-lactamases can now confer resistance to other β-lactam drugs, including both cephalosporins and carbapenems. The emergence and global spread of β-lactamase-producing multi-drug-resistant “superbugs” has caused increased alarm within the medical community due to the high mortality rate associated with these difficult-to-treat bacterial infections. To address this unmet medical need, we initiated an iterative program combining medicinal chemistry, structural biology, biochemical testing, and microbiological profiling to identify broad-spectrum inhibitors of both serine- and metallo-β-lactamase enzymes. Lead optimization, beginning with narrower-spectrum, weakly active compounds, provided 20 (VNRX-5133, taniborbactam), a boronic-acid-containing pan-spectrum β-lactamase inhibitor. In vitro and in vivo studies demonstrated that 20 restored the activity of β-lactam antibiotics against carbapenem-resistant Pseudomonas aeruginosa and carbapenem-resistant Enterobacteriaceae. Taniborbactam is the first pan-spectrum β-lactamase inhibitor to enter clinical development.

Three new uranium species (C5Me5)2U([double bond, length as m-dash]N-2,6-iPr2-C6H3)([double bond, length as m-dash]S), (C5Me5)2U([double bond, length as m-dash]N-2,6-iPr2-C6H3)(η2-S2), and (C5Me5)2U([double bond, length as m-dash]N-2,6-iPr2-C6H3)(S[double bond, length as m-dash]PMe3) were synthesized and fully characterized by a combination of NMR, IR, and UV/vis-NIR spectroscopies, elemental analysis, and cyclic voltammetry. The solid state structures of (C5Me5)2U([double bond, length as m-dash]N-2,6-iPr2-C6H3)([double bond, length as m-dash]S) and (C5Me5)2U([double bond, length as m-dash]N-2,6-iPr2-C6H3)(η2-S2) were also determined. The compound (C5Me5)2U([double bond, length as m-dash]N-2,6-iPr2-C6H3)([double bond, length as m-dash]S) is the first neutral uranium complex with a terminal sulphido ligand, and (C5Me5)2U([double bond, length as m-dash]N-2,6-iPr2-C6H3)(S[double bond, length as m-dash]PMe3) is the first uranium compound with a coordinated phosphine sulphide ligand. The phosphine sulphide adduct, (C5Me5)2U([double bond, length as m-dash]N-2,6-iPr2-C6H3)(S[double bond, length as m-dash]PMe3), can be synthesized either by reaction of the uranium(iv) complex (C5Me5)2U([double bond, length as m-dash]N-2,6-iPr2-C6H3)(thf) with S[double bond, length as m-dash]PMe3 or by the reaction of the uranium(vi) terminal sulphido complex (C5Me5)2U([double bond, length as m-dash]N-2,6-iPr2-C6H3)([double bond, length as m-dash]S) with PMe3.

The use of copper catalysis with visible light photoredox catalysis in a cooperative fashion has recently emerged as a versatile means of developing new C–C bond forming reactions. In this work, dual copper and photoredox catalysis is exploited to effect C(sp2)–C(sp3) cross-couplings between aryl boronic acids and benzyl bromides.

Identifying biologically relevant molecular targets of oxidative stress may provide new insights into disease mechanisms and accelerate development of novel biomarkers. Ribosome biogenesis is a fundamental prerequisite for cellular protein synthesis, but how oxidative stress affects ribosome biogenesis has not been clearly established. To monitor and control the redox environment of ribosome biogenesis, we targeted a redox-sensitive roGFP reporter and catalase, a highly efficient H2O2 scavenger, to the nucleolus, the primary site for transcription and processing of rRNA in eukaryotic cells. Imaging of mouse 3T3 cells exposed to non-cytotoxic H2O2 concentrations revealed increased oxidation of the nucleolar environment accompanied by a detectable increase in the oxidative damage marker 8-oxo-G in nucleolar RNA. Analysis of pre-rRNA processing showed a complex pattern of alterations in pre-rRNA maturation in the presence of H2O2, including inhibition of the transcription and processing of the primary 47S transcript, accumulation of 18S precursors, and inefficient 3′-end processing of 5.8S rRNA. This work introduces new tools for studies of the redox biology of the mammalian nucleolus and identifies pre-rRNA maturation steps sensitive to H2O2 stress.

Signal Amplification by Reversible Exchange (SABRE) is an inexpensive and simple hyperpolarization technique that is capable of boosting nuclear magnetic resonance sensitivity by several orders of magnitude. It utilizes the reversible binding of para-hydrogen, as hydride ligands, and a substrate of interest to a metal catalyst to allow for polarization transfer from para-hydrogen into substrate nuclear spins. While the resulting nuclear spin populations can be dramatically larger than those normally created, their lifetime sets a strict upper limit on the experimental timeframe. Consequently, short nuclear spin lifetimes are a challenge for hyperpolarized metabolic imaging. In this report, we demonstrate how both hyperpolarization and long nuclear spin lifetime can be simultaneously achieved in nitrogen-15 containing derivatives of pyridazine and phthalazine by SABRE. These substrates were chosen to reflect two distinct classes of 15N2-coupled species that differ according to their chemical symmetry and thereby achieve different nuclear spin lifetimes. The pyridazine derivative proves to exhibit a signal lifetime of �2.5 min and can be produced with a signal enhancement of �2700. In contrast, while the phthalazine derivative yields a superior 15 000-fold 15N signal enhancement at 11.7 T, it has a much shorter signal lifetime.

As shifts in the epidemiology of β-lactamase-mediated resistance continue, carbapenem-resistant Enterobacterales (CRE) and carbapenem-resistant Pseudomonas aeruginosa (CRPA) are the most urgent threats. Although approved β-lactam (BL)-β-lactamase inhibitor (BLI) combinations address widespread serine β-lactamases (SBLs), such as CTX-M-15, none provide broad coverage against either clinically important serine-β-lactamases (KPC, OXA-48) or clinically important metallo-β-lactamases (MBLs; e.g., NDM-1). VNRX-5133 (taniborbactam) is a new cyclic boronate BLI that is in clinical development combined with cefepime for the treatment of infections caused by β-lactamase-producing CRE and CRPA. Taniborbactam is the first BLI with direct inhibitory activity against Ambler class A, B, C, and D enzymes. From biochemical and structural analyses, taniborbactam exploits substrate mimicry while employing distinct mechanisms to inhibit both SBLs and MBLs. It is a reversible covalent inhibitor of SBLs with slow dissociation and a prolonged active-site residence time (half-life, 30 to 105 min), while in MBLs, it behaves as a competitive inhibitor, with inhibitor constant (Ki ) values ranging from 0.019 to 0.081 μM. Inhibition is achieved by mimicking the transition state structure and exploiting interactions with highly conserved active-site residues. In microbiological testing, taniborbactam restored cefepime activity in 33/34 engineered Escherichia coli strains overproducing individual enzymes covering Ambler classes A, B, C, and D, providing up to a 1,024-fold shift in the MIC. Addition of taniborbactam restored the antibacterial activity of cefepime against all 102 Enterobacterales clinical isolates tested and 38/41 P. aeruginosa clinical isolates tested with MIC90s of 1 and 4 μg/ml, respectively, representing ≥256- and ≥32-fold improvements, respectively, in antibacterial activity over that of cefepime alone. The data demonstrate the potent, broad-spectrum rescue of cefepime activity by taniborbactam against clinical isolates of CRE and CRPA.

Speleothem trace element ratios such as Mg/Ca and Sr/Ca are increasingly used in speleothem paleoclimatology as a supplement to stable oxygen and carbon isotope ratios as proxies for past variability in the hydrologic system. Using multiple proxies together allows for a better understanding of both the local and distal hydrologic changes recorded in speleothem chemistry, and therefore of changes in past rainfall. Despite the potential benefits, trace element analysis of speleothems has yet to become widespread, which is likely due to the significant time and costs required by traditional trace element analytical techniques. In this study, we present an in-depth investigation into a rapid, relatively non-destructive and competitively priced technique for measuring Sr/Ca in speleothems: Core-Scanning micro X-ray Fluorescence (CS-μXRF). We show that CS-μXRF reliably and precisely records Sr concentration in speleothems. Ratioed to near-stoichiometric Ca, the Sr/Ca ratio accounts for variations in beam strength and machine settings, producing a more reliable reported measurement for both intra- and inter-run comparisons. CS-μXRF compares favorably with more conventional trace element procedures such as Quadrupole ICP-MS and ICP-AES, giving confidence in the ability of CS-μXRF to produce paleoclimatologically significant Sr/Ca results. We also identify secondary issues relating to speleothem crystallinity, the dominance of Ca spectral peaks, and comparatively lower energy X-rays that can interfere with precise CS-μXRF analyses. If these can be overcome then CS-μXRF may provide an even more useful method of trace element analysis in speleothem studies.

Despite a good initial response to front-line chemotherapy, majority of the ovarian cancer patients relapse with consecutive phases of recurrences; and nearly 60% die within 5 years due to the development of a chemoresistant disease. This study investigated whether inhibition of the Janus kinase 2 (JAK2)-signal transducer and activator of transcription 3 (STAT3) pathway by momelotinib is sufficient in suppressing tumor burden and prolonging the disease-free survival period in a mouse model of ovarian cancer. We demonstrate that paclitaxel treatment enhanced JAK2/STAT3 activation which resulted in the enrichment of cancer stem cell (CSC)-like phenotype in the surviving ovarian cancer cells in vitro and in in vivo mouse xenografts. Combined treatment with paclitaxel and momelotinib inhibited paclitaxel-induced JAK2/STAT3 activation and CSC-like development in mice xenografts, and consequently reduced the tumor burden significantly greater than that achieved by paclitaxel-treatment alone. However, robust recurrent tumor growth with enhanced JAK2/STAT3 activation and CSC-like phenotype was observed in all mice groups after termination of treatments, but was delayed significantly in the paclitaxel and momelotinib treated group compared to other treatment groups. Daily oral gavage of momelotinib after termination of paclitaxel treatment showed sustained inhibition of tumor growth and a prolonged disease-free survival period in 50% of the mice. The other 50% of mice that developed tumors with ongoing momelotinib treatment also showed significantly increased survival benefit and a smaller tumor burden. These preliminary findings may have a profound clinical impact in developing an effective momelotinib-based ‘maintenance-therapy’ in ovarian cancer patients' post-chemotherapy treatment.

A number of diazepines are known to inhibit bromo- and extra-terminal domain (BET) proteins. Their BET inhibitory activity derives from the fusion of an acetyl-lysine mimetic heterocycle onto the diazepine framework. Herein we describe a straightforward, modular synthesis of novel 1,2,3-triazolobenzodiazepines and show that the 1,2,3-triazole acts as an effective acetyl- lysine mimetic heterocycle. Structure-based optimization of this series of compounds led to the development of potent BET bromodomain inhibitors with excellent activity against AF9-MLL-driven leukemic cells, concomitant with a reduction in c-MYC expression. These novel benzodiazepines therefore represent a promising class of therapeutic BET inhibitors

KRAS-G12C is an important oncogenic mutation in patients with NSCLC, CRC, and other cancer types. Currently, there are no FDA-approved KRAS-G12C inhibitors, and those in clinical development have relatively modest activity compared to other approved therapies targeting other classic oncogenic drivers. This modest activity may be potentially due in part to incomplete target occupancy and trapping of mutant KRAS in the inactive GDP-bound state. Achieving maximal clinical benefit in patients harboring a KRAS-G12C mutation, may require a potent inhibitor capable of achieving near complete target engagement. Here, we report the identification of LY3537982, a novel, highly selective and potent inhibitor of the KRAS-G12C protein, discovered using structure-based design. In kinetic studies, LY3537982 showed a high Kinact/Ki value (248,016 M-1 s-1), compared to AMG510 (7,220 M-1 s-1) and MRTX849 (35,000 M-1 s-1). LY3537982 inhibited KRAS-GTP loading with an IC50 value of 3.35 nM in the KRAS-G12C mutant H358 lung cancer cell line, while AMG510 and MRTX849 had IC50 values of 47.9 nM and 89.9 nM, respectively. LY3537982 also inhibited phospho-ERK in H358 cells with an IC50 value of 0.65 nM, while the IC50 values of AMG510 and MRTX849 were 13.5 nM and 14 nM, respectively. In a panel of cancer cell lines with KRAS-G12C or non-G12C mutations, LY3537982 selectively inhibited the growth of KRAS-G12C mutant tumor cells and not KRAS wild-type or non-G12C mutant cells. Sensitivity to LY3537982 varied among the KRAS-G12C mutant cells tested, suggesting that not all cell lines maintain the same dependence on KRAS-G12C. Similarly, in multiple xenograft or patient-derived xenograft (PDX) models harboring a KRAS-G12C mutation, LY3537982 exhibited a range of anti-tumor activity from complete regression to significant tumor growth inhibition, at 3 to 30 mg/kg QD or BID. Mechanism-based combinational screens have also identified certain targeted therapies that can synergize with LY3537982 to achieve better anti-tumor activity in vitro and in vivo, including abemaciclib, the selective AurA inhibitor LY3295668, and cetuximab. Together these data suggest that in certain biologic contexts, broader and more durable anti-tumor activity could be achieved with combination regimens. A first-in-human Phase 1 clinical trial is planned for 2021. Citation Format: Sheng-Bin Peng, Chong Si, Youyan Zhang, Robert D. Van Horn, Xi Lin, Xueqian Gong, Lysiane Huber, Gregory Donoho, Carmen Curtis, John M. Strelow, Wayne P. Bocchinfuso, Deqi Guo, Serge L. Boulet, David Barda, Danalyn Manglicmot, Melbert-Brian D. Saflor, Jing Wang, Junpeng Xiao, Michael J. Chalmers, Lee Burns, Ryan J. Linder, Bradley L. Ackermann, Paul D. Cornwell, Lian Zhou, Denis McCann, James Henry. Preclinical characterization of LY3537982, a novel, highly selective and potent KRAS-G12C inhibitor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1259.

A comprehensive study is presented of the characteristics of calcareous concretions in the Connecticut Valley varved clay (CVVC), a glacial lake sediment, probed by an array of investigations, including compositional analyses via X-ray powder diffraction and energy-dispersive X-ray spectroscopy, mechanical property mapping by nanoindentation, selective dissolution, microstructure examination by optical and electron microscopy, and stable isotope analyses, with an objective to resolve some long-standing questions on their origin and growth mechanisms. Results show that these concretions are of a biogenic origin and consist of ~40 wt% primary host sediments and ~ 60 wt% secondary calcite post-depositionally precipitated as pore infills and inter-particle cement. The highly consistent layering and dry density between the carbonate-free host sediments in the concretions and in-situ varved sediments manifest that the precipitated calcite causes no disturbance to the original stratification and structure of the varved sediments. Moreover, both the mechanical properties (i.e., Young's modulus and hardness) and calcite concentration in concretions exhibit a radially decreasing pattern slightly disturbed by the sediments' layered textures. Further supported by the radial distribution patterns of stable carbon and oxygen isotopes, the CVVC concretions grow in a concentric pattern. A conceptual ion transport model is proposed to further interpret the growth mechanisms. These concretions grow radially in a nearly closed sediment system with diffusion-controlled transport of HCO3− from decaying organic matter and Ca2+ from porewater at direction-dependent rates dominated by the pore characteristics of the local host sediments. The diverse concretion morphologies are attributed to the different growth rates in different directions affected by the heterogeneous layering and pore sizes of the host sediments.

Although heavy alcohol consumption is associated with diabetes-related complications, little is known about patterns of alcohol use among people with diabetes. Moreover, heavy drinking is more common among individuals with major depressive disorder (MDD), bipolar disorder (BD), and generalized anxiety disorder (GAD) than in the general population, and these disorders are often comorbid with diabetes. The present study tested the hypothesis that mental disorders moderate the association between diabetes status and alcohol consumption. A total of 14,302 adult participants aged 40-79 were included from the cross-sectional 2012 Canadian Community Health Survey-Mental Health (1,698 with diabetes). Data were analyzed using hierarchical linear regression models. MDD and BD, but not GAD, significantly moderated the association between diabetes status and alcohol quantity, such that the presence of diabetes was strongly and negatively associated with alcohol quantity if individuals had MDD or BD. There was no interaction between diabetes status and any of the mental disorders and alcohol frequency. This study suggests that among individuals with diabetes, those with comorbid MDD or BD drink less than those without MDD or BD. Further investigation of this association is needed and could help inform future alcohol-related interventions among individuals with diabetes.

A new type of synthesis, referred to as oxidative methylation, is developed for [Cp*2Yb]2(μ-X) and [Cp*2Yb]2(μ-X)(X), where X = Me, using MeCu or Cp*2VMe as the methyl transfer reagent and Cp*2Yb. The synthetic methodology is extended to other X derivatives such as the halides and BH4. Reaction of [Cp*2Yb]2(μ-Me)(Me) and H2 yields the mixed-valent hydride [Cp*2Yb]2(μ-H), which eliminates H2 on gentle heating, forming Cp*2Yb. When Cp*2VX is replaced by Cp*2TiX, 1:1 adducts based upon Ti(III,d1) are isolated. The X-ray crystal structure of [Cp*2Yb](μ-Me)[TiCp*2] shows that the methyl group bridges the two different decamethylmetallocene fragments in a near-linear fashion, a geometry that is likely to resemble the transition state of the single-electron-transfer precursor complex. A CASSCF computational study on the mixed-valent hydride [Cp*2Yb]2(μ-H) shows that the ground state is a spin doublet in which the hydride forms a symmetric bridge to both Yb atoms. The three spins forming the ground-state doublet ...

The solution chemistry and solid state structures of the Co(II), Fe(II), and Ni(II) complexes of N,N′-bis(imidazole-2-ylmethyl)-4,10-diaza-15-crown-5 (HINO) are reported. The Co(II) and Ni(II) complexes of HINO are the first examples of paraCEST agents (paramagnetic chemical exchange saturation transfer) that feature exchangeable imidazole NH protons. The crystal structures of [Co(HINO)]CoCl4·H2O and [Fe(HINO)](CF3SO3)2 have the metal ions coordinated to four nitrogen and three oxygen donor atoms of the macrocyclic ligand in a distorted pentagonal bipyramidal geometry. In [Ni(HINO)](CF3SO3)2, the nickel ion is bound to only two of the three ether oxygens and three nitrogens to produce a complex with a distorted octahedral geometry. The 1H NMR spectra of the three paramagnetic complexes show resonances characteristic of effective C2 symmetry in solution. CEST peaks attributed to the imidazole NH proton of the pendent group are observed at 32 and 55 ppm away from bulk water for [Co(HINO)]2+ and [Ni(HINO)]2+...

Nitrogen is a key limiting resource for biomass production in the marine environment. Methylated amines, released from the degradation of osmolytes, could provide a nitrogen source for marine microbes. Thus far, studies in aquatic habitats on the utilization of methylamine, the simplest methylated amine, have mainly focussed on the fate of the carbon from this compound. Various groups of methylotrophs, microorganisms that can grow on one-carbon compounds, use methylamine as a carbon source. Non-methylotrophic microorganisms may also utilize methylamine as a nitrogen source, but little is known about their diversity, especially in the marine environment. In this proof-of-concept study, stable isotope probing (SIP) was used to identify microorganisms from a coastal environment that assimilate nitrogen from methylamine. SIP experiments using 15N methylamine combined with metagenomics and metaproteomics facilitated identification of active methylamine-utilizing Alpha- and Gammaproteobacteria. The draft genomes of two methylamine utilizers were obtained and their metabolism with respect to methylamine was examined. Both bacteria identified in these SIP experiments used the γ-glutamyl-methylamide pathway, found in both methylotrophs and non-methylotrophs, to metabolize methylamine. The utilization of 15N methylamine also led to the release of 15N ammonium that was used as nitrogen source by other microorganisms not directly using methylamine. This article is protected by copyright. All rights reserved.

Methods for positionally selective remote C−H functionalizations are in high demand. Herein, we disclose the first heterogeneous ruthenium catalyst for meta-selective C−H functionalizations, which enabled remote halogenations with excellent site selectivity and ample scope. The versatile heterogeneous Ru@SiO2 catalyst was broadly applicable and could be easily recovered and reused, which set the stage for the direct fluorescent labeling of purines. In contrast to palladium, rhodium, iridium, or cobalt complexes, solely the ruthenium catalysis manifold provided access to meta-halogenated purine derivatives, illustrating the unique power of ruthenium C−H activation catalysis.

The intervertebral disk (IVD) is a composite structure essential for spine stabilization, load bearing, and movement. Biomechanical factors are important contributors to the IVD microenvironment regulating joint homeostasis; however, the cell type‐specific effectors of mechanotransduction in the IVD are not fully understood. The current study aimed to determine the effects of cyclic tensile strain (CTS) on annulus fibrosus (AF) cells and identify mechano‐sensitive pathways. Using a cell‐type specific reporter mouse to differentiation NP and AF cells from the murine IVD, we characterized AF cells in dynamic culture exposed to CTS (6% strain) at specific frequencies (0.1 Hz, 1.0 Hz, or 2.0 Hz). We demonstrate that our culture model maintains the phenotype of primary AF cells and that the bioreactor system delivers uniform biaxial strain across the cell culture surface. We show that exposure of AF cells to CTS induces cytoskeleton reorganization resulting in stress fiber formation, with acute exposure to CTS at 2.0 Hz inducing a significant yet transient increase ERK1/2 pathway activation. Using SYBPR‐based qPCR to assess the expression of extracellular matrix (ECM) genes, ECM‐remodeling genes, candidate mechano‐sensitive genes, inflammatory cytokines and cell surface receptors, we demonstrated that exposure of AF cells to CTS at 0.1 Hz increased Acan, Prg4, Col1a1 and Mmp3 expression. AF cells exposed to CTS at 1.0 Hz showed a significant increase in the expression of Acan, Myc, and Tnfα. Exposure of AF cells to CTS at 2.0 Hz induced a significant increase in Acan, Prg4, Cox2, Myc, Fos, and Tnfα expression. Among the cell surface receptors assessed, AF cells exposed to CTS at 2.0 Hz showed a significant increase in Itgβ1, Itgα5, and Trpv4 expression. Our findings demonstrate that the response of AF cells to CTS is frequency dependent and suggest that mechanical loading may directly contribute to matrix remodeling and the onset of local tissue inflammation in the murine IVD.

The release of abiotic methane from marine seeps into the atmosphere is a major source of this potent greenhouse gas. Methanotrophic microorganisms in methane seeps use methane as carbon and energy source, thus significantly mitigating global methane emissions. Here, we investigated microbial methane oxidation at the sediment-water interface of a shallow marine methane seep. Metagenomics and metaproteomics, combined with 13 C-methane stable isotope probing, demonstrated that various members of the gammaproteobacterial family Methylococcaceae were the key players for methane oxidation, catalysing the first reaction step to methanol. We observed a transfer of carbon to methanol-oxidizing methylotrophs of the betaproteobacterial family Methylophilaceae, suggesting an interaction between methanotrophic and methylotrophic microorganisms that allowed for rapid methane oxidation. From our microcosms, we estimated methane oxidation rates of up to 871 nmol of methane per gram sediment per day. This implies that more than 50% of methane at the seep is removed by microbial oxidation at the sediment-water interface, based on previously reported in situ methane fluxes. The organic carbon produced was further assimilated by different heterotrophic microbes, demonstrating that the methane-oxidizing community supported a complex trophic network. Our results provide valuable eco-physiological insights into this specialized microbial community performing an ecosystem function of global relevance.

Zinc (Zn) is an essential trace metal required for all forms of life, but is toxic at high concentrations. While the toxic effects of high levels of Zn are well documented, the mechanism of cell death appears to vary based on the study and concentration of Zn. Zn has been proposed as an anti-cancer treatment against non-small cell lung cancer (NSCLC). The goal of this analysis was to determine the effects of Zn on metabolism and cell death in A549 cells. Here, high throughput multi-omics analysis identified the molecular effects of Zn intoxication on the proteome, metabolome, and transcriptome of A549 human NSCLC cells after 5 min to 24 h of Zn exposure. Multi-omics analysis combined with additional experimental evidence suggests Zn intoxication induces ferroptosis, an iron and lipid peroxidation-dependent programmed cell death, demonstrating the utility of multi-omics analysis to identify cellular response to intoxicants.

Holistic perception is a special form of automatic and experience dependent processing that prioritises objects of interest through the visual system. We therefore speculated that higher levels of alcohol consumption may be associated with enhanced holistic perception for alcohol cues. In our first experiment, we confirmed this hypothesis by showing that increasing regular alcohol usage was associated with greater holistic perception of alcohol, but not non-alcohol, cues. We replicated this finding in a second experiment, but confirmed drink-specific holistic perception for lager cues was not predicted by experience with that drink, but general alcohol usage. In our final experiment when alcohol images were absent from the task, higher levels of alcohol consumption predicted decreased holistic perception for non-rewarding cues. Alcohol use is therefore linked to inverse alterations in holistic perception for alcohol versus non-alcohol cues, with the latter's effects context dependent. We hypothesise that such inverse relationships may be due to limited cortical resources becoming reutilised for alcohol cues at the expense of other stimuli. Future work will be required to determine holistic perception's role in maintaining addiction, its predictive value in successful abstinence, and its relationship with characteristics of addiction such as cue reactivity, attentional biases and personality traits.

The inclusion complexes of composition (Cp*2Yb)2(Cp2M) (M = V, Cr, Fe, and Co; Cp* = η5-C5Me5; Cp = η5-C5H5) are isolated in the solid state. The crystal structure of one of them, M = Co, shows that the Cp2Co metallocene is sandwiched between two Cp*2Yb metallocenes with two long Yb···C bond distances of 2.914(6) A, one from each of the Cp rings of Cp2Co. When M = Mn and Ni are used, the ring exchange products, Cp*MCp, are isolated along with Cp*YbCp, a hydrocarbon-insoluble green solid isolated as the thf adduct. This Cp for Cp* exchange reaction is the only currently available synthesis for the low-spin pentamethylmanganocene and the pentamethylytterbocene. The crystal structures and magnetic and related physical properties of Cp*MCp, M = Mn, Co, and Ni (Organometallics 1985, 4, 1680), are reported and analyzed. The origin of the different relative rates of Cp* for Cp ring exchange is traced to the kinetic lability resulting from the (e1g*)2 electronic structure of Cp2M, M = Mn and Ni.

We present analytical simulations for the performance of nano-coaxial and -hemispherical drift-limited solar cells, to determine optimal geometrical configuration and to interpret results of experimental nanocoaxial solar cell arrays. The material system considered in these simulations is hydrogenated amorphous silicon (a-Si:H), with solar cells designed in an n–i–p stack. Simulations conducted for the performance of planar devices are compared against simulations performed using SCAPS-1D and are found to be in close agreement. Simulation of the nanocoaxial array shows that while geometrical changes in the energy band diagram impact charge carrier collection, performance is most significantly impacted by light absorption properties associated with incident light interacting with the array of non-planar nanostructures. We compare our simulations to results of fabricated nanocoaxial a-Si:H solar cells.

Laboratory experiments that demonstrate the effect of paramagnetic complexes on chemical shifts and relaxation times of protons are a useful way to introduce magnetic resonance spectroscopy (MRS) probes or magnetic resonance imaging (MRI) contrast agents. In this undergraduate inorganic chemistry experiment, a paramagnetic Co(II) cage complex is prepared by reduction of a classical Co(III) cage complex. The Co(II) cage behaves as a paramagnetic shift agent (paraSHIFT) and produces relatively sharp and highly dispersed proton resonances. Comparison of the proton NMR spectra of the diamagnetic and paramagnetic cage complexes provides opportunities for students to consider coordination complex symmetry and the effect of unpaired electrons on the chemical shifts of proton resonances. Oxidation and spin state changes of transition metal complexes, Co(III)/Co(II), are also illustrated in this experiment.

Summary: Stimulator of Interferon Genes (STING) is a critical component of host innate immune defense but can contribute to chronic autoimmune or autoinflammatory disease. Once activated, the cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) (cGAMP) synthase (cGAS)-STING pathway induces both type I interferon (IFN) expression and nuclear factor-κB (NF-κB)-mediated cytokine production. Currently, these two signaling arms are thought to be mediated by a single upstream kinase, TANK-binding kinase 1 (TBK1). Here, using genetic and pharmacological approaches, we show that TBK1 alone is dispensable for STING-induced NF-κB responses in human and mouse immune cells, as well as in vivo. We further demonstrate that TBK1 acts redundantly with IκB kinase ε (IKKε) to drive NF-κB upon STING activation. Interestingly, we show that activation of IFN regulatory factor 3 (IRF3) is highly dependent on TBK1 kinase activity, whereas NF-κB is significantly less sensitive to TBK1/IKKε kinase inhibition. Our work redefines signaling events downstream of cGAS-STING. Our findings further suggest that cGAS-STING will need to be targeted directly to effectively ameliorate the inflammation underpinning disorders associated with STING hyperactivity. : Activation of NF-κB via STING is considered to be exclusively dependent on TBK1. Balka et al. now show that, although TBK1 and its kinase activity are critical for IRF3 activation and type I IFNs, it is dispensable for NF-κB. Instead, TBK1 and IKKε act redundantly to mediate STING-induced NF-κB responses. Keywords: STING, cGAS, innate immunity, NF-κB, TBK1, IKKε, signal transduction, type I interferons, cytokines, protein kinases

Anodized alumina membranes (AAMs) have proven effective at making vertically-oriented and well-ordered metal nanowire arrays, which are useful in plasmonics and electrochemistry. Here, we produced Al nanowires via directed AAM pore nucleation: a patterned oxide mask on a flat Al surface directed where pores did and did not form, the pores acting to oxidize Al around the sites without pores. This left Al nanowires embedded in the AAM, and produced freestanding Al nanowires after etching the AAM. The nanowire tops had two distinct contours, smooth bowls and flat rough surfaces-suggesting that nanowires with bowl tops result from slow pore development relative to pattern-nucleated pores, not pore blockage as prior literature suggests. The observed low porosity of ∼2%, as opposed to the more typical 10%, suggests pore nucleation in the electrolyte employed may need greater local variations in electric field or pH, possibly explaining the electrolyte's peculiar ability to make Al nanowires. Finally, a soft nano-imprint lithography process was developed here to pattern the mask without damaging the stamp, avoiding a stamp degradation problem in previous work that utilized hard nano-imprint lithography.

This corrects the article DOI: 10.1103/PhysRevLett.119.175702.

The first total synthesis of phacelocarpus 2-pyrone A is reported. The original natural compound was tentatively assigned (by NMR spectroscopy) as containing two cis-alkenes and a trans-vinyl ether connected to a 2-pyrone ring motif. Our computational predictions indicated that a cis-vinyl ether motif was equally feasible. Attempts to prepare the trans-vinyl ether were met with no success. The all cis-target compound was synthesised in nine steps, employing key regio- and stereoselective reactions including Au(I)-catalysed vinyl etherification, Wittig alkenylation and end-game Stille macrocyclisation. Analysis of the NMR data enabled identification and confirmation of the correct structure of phacelocarpus 2-pyrone A, containing a cis-vinyl ether. Our studies pave the way for future development of methodologies to these structurally distinct pyrone skipped-polyenyne natural products.

Freestanding and vertically-oriented metal nanowire arrays have potential utility in a number of applications, but presently lack a route to fabrication. Template-based techniques, such as electrodeposition into lithographically defined nanopore arrays, have produced well-ordered nanowire arrays with a maximum pitch of about 2 μm; such nanowires, however, tend to cluster due to local attractive forces. Here, we modify this template fabrication method to produce well-ordered, vertically-oriented, freestanding Al nanowire arrays, etched from an underlying Al substrate, with highly tunable pitch. In addition, optical measurements demonstrated that the nanowires support the propagation of surface plasmon polaritons.

The serine-threonine kinase CDK9 is a target of emerging interest for the development of anti-cancer drugs. There are multiple lines of evidence linking CDK9 activity to cancer, including the essential role this kinase plays in transcriptional regulation through phosphorylation of the C-terminal domain (CTD) of RNA polymerase II. Indeed, inhibition of CDK9 has been shown to result in a reduction of short-lived proteins such as the pro-survival protein Mcl-1 in malignant cells leading to the induction of apoptosis. In this work we report our initial studies towards the discovery of selective CDK9 inhibitors, starting from the known multi-kinase inhibitor PIK-75 which possesses potent CDK9 activity. Our series is based on a pyrazolo[1,5-a]pyrimidine nucleus and, importantly, the resultant lead compound 18b is devoid of the structural liabilities present in PIK-75 and possesses greater selectivity.

This study uses acute doses of three test radiations, [40Ar ions (L = 125 keVμ−1), 20Ne ions (L = 25 keVμ−1) and electron radiation] to examine a potential quantitative link between rat skin cancer induction and gamma-H2AX foci in rat keratinocytes exposed in vitro to radiations with comparable L values. Theory provided a testable link between cancer yield and gamma-H2AX foci yields: YCa(D,L)rat−1 = (NF)2−1YAX(D,L)keratinocyte−1 (eqn 1), where YCa(D,L) is cancers(rat) −1 at 1.0 y, YAX(D,L) is in vitro gamma-H2AX foci(keratinocyte) −1, D is radiation dose, L is linear energy transfer, N is irradiated keratinocytes in vivo, and F is the error rate of end joining. An explicit expression for cancer yield was derived based on cancers arising in the ion track region in proportion to D and L (first term) and independently in proportion to D2 in the delta ray region in between the ion tracks (second term): YCa(D,L) = CCaLD + BCaD2 (eqn 1a). Parameters quantified include: CCa = 0.000589 ± 0.000150 cancers-micron[rat(kev)Gy]−1; BCa = 0.0088 ± 0.0035 cancers(ratGy2)−1, F = (8.18 ± 0.91) × 10−10; N = (8.8 ± 1.2) × 107 and (NF)2−1 = 0.036 ± 0.006 cancer keratinocyte(rat H2AX foci)−1. Verification of eqns (1) and (1a) and the constancy of F support the hypothesis that end-rejoining errors play a major role in radiation carcinogenesis in rat skin. Cancer yields per rat were consistently predictable based on gamma-H2AX foci yields in keratinocytes in vitro such that 27.8 H2AXfoci(keratinocyte)−1 predicted 1.0 cancer(rat)−1 at 1 y.

1,3-Enynes containing allylic hydrogens cis to the alkyne function as three-carbon components in rhodium(III)-catalyzed, all-carbon [3+3] oxidative annulations to produce spirodialins. The proposed mechanism of these reactions involves the alkenyl-to-allyl 1,4-rhodium(III) migration.

Isomerisation of buta-1,2-diene to but-2-yne by (Me(5)C(5))(2)Yb is a thermodynamically favourable reaction, with the Δ(r)G° estimated from experimental data at 298 K to be -3.0 kcal mol(-1). It proceeds in hydrocarbon solvents with a pseudo first-order rate constant of 6.4 × 10(-6) s(-1) and 7.4 × 10(-5) s(-1) in C(6)D(12) and C(6)D(6), respectively, at 20 °C. This 1,3-hydrogen shift is formally forbidden by symmetry and has to occur by an alternative pathway. The proposed mechanism for buta-1,2-diene to but-2-yne isomerisation by (Me(5)C(5))(2)Yb involves coordination of methylallene (buta-1,2-diene) to (Me(5)C(5))(2)Yb, and deprotonation of methylallene by one of the Me(5)C(5) ligands followed by protonation of the terminal methylallenyl carbon to yield the known coordination compound (Me(5)C(5))(2)Yb(η(2)-MeC[triple bond, length as m-dash]CMe). Computationally, this mechanism is not initiated by a single electron transfer step, and the ytterbium retains its oxidation state (II) throughout the reactivity. Experimentally, the influence of the metal centre is discussed by comparison with the reaction of (Me(5)C(5))(2)Ca towards buta-1,2-diene, and (Me(5)C(5))(2)Yb with ethylene. The mechanism by which the Me(5)C(5) acts as a proton-relay within the coordination sphere of a metal also rationalises the reactivity of (i) (Me(5)C(5))(2)Eu(OEt(2)) with phenylacetylene, (ii) (Me(5)C(5))(2)Yb(OEt(2)) with phenylphosphine and (iii) (Me(5)C(5))(2)U(NPh)(2) with H(2) to yield (Me(5)C(5))(2)U(HNPh)(2). In the latter case, the computed mechanism is the heterolytic activation of H(2) by (Me(5)C(5))(2)U(NPh)(2) to yield (Me(5)C(5))(2)U(H)(HNPh)(NPh), followed by a hydrogen transfer from uranium back to the imido nitrogen atom using one Me(5)C(5) ligand as a proton-relay. The overall mechanism by which hydrogen shifts using a pentamethylcyclopentadienyl ligand as a proton-relay is named Carambole in reference to carom billiards.

The use of aluminum (Al) as a plasmonic building block has drawn increasing attention of late, due to its natural abundance, and extended tunability into the ultraviolet range. However, a controllable way to grow Al nanowires (NWs) in a bottom-up manner has not been reported. Here a facile, stress-induced growth process for Al nanowires, influenced by the concentration of applied hydrofluoric acid, is reported. Physical characterizations show the nanowires to be polycrystalline fcc Al with ultrasmooth surfaces, with many possible cross-section geometries, making them potential candidates for Al plasmonic investigations and applications. Dark-field optical analysis of a crescent-shaped Al NW demonstrates its plasmonic nature. These results may stimulate new interest in the fabrication of unconventional, nearly one dimensional Al nanostructures.

We present measured light outputs from a series of oleic acid and alkyl functionalized CdSeS/ZnS quantum dots in toluene and water-based suspensions. The colloidal nanocrystal samples were studied under UV and X-ray excitation, and in the presence of radioactive isotopes. Low-concentration (1 mg/ml) samples as small as 1 ml exhibited a measurable response to radiation exposure.

Pseudomonas aeruginosa and Staphylococcus aureus are commonly isolated from polymicrobial infections, such as wound infections and chronic respiratory infections of persons with cystic fibrosis. Despite their coisolation, P. aeruginosa produces substances toxic to S. aureus , including pyocyanin, a blue-pigmented molecule that functions in P. aeruginosa virulence. Pyocyanin inhibits S. aureus respiration, forcing it to derive energy from fermentation and adopt a small-colony variant (SCV) phenotype. The mechanisms by which S. aureus sustains infection in the presence of pyocyanin are not clear. We sought to clarify the mechanisms of pyocyanin toxicity in S. aureus as well as identify the staphylococcal factors involved in its resistance to pyocyanin toxicity. Nonrespiring S. aureus SCVs are inhibited by pyocyanin through pyocyanin-dependent reactive oxygen species (ROS) production, indicating that pyocyanin toxicity is mediated through respiratory inhibition and ROS generation. Selection on pyocyanin yielded a menadione auxotrophic SCV capable of growth on high concentrations of pyocyanin. Genome sequencing of this isolate identified mutations in four genes, including saeS , menD , NWMN_0006, and qsrR . QsrR is a quinone-sensing repressor of quinone detoxification genes. Inactivation of qsrR resulted in significant pyocyanin resistance, and additional pyocyanin resistance was achieved through combined inactivation of qsrR and menadione biosynthesis. Pyocyanin-resistant S. aureus has an enhanced capability to inactivate pyocyanin, suggesting QsrR-regulated gene products may degrade pyocyanin to alleviate toxicity. These findings demonstrate pyocyanin-mediated ROS generation as an additional mechanism of pyocyanin toxicity and define QsrR as a key mediator of pyocyanin resistance in S. aureus . IMPORTANCE Many bacterial infections occur in the presence of other microbes, where interactions between different microbes and the host impact disease. In patients with cystic fibrosis, chronic lung infection with multiple microbes results in the most severe disease manifestations. Staphylococcus aureus and Pseudomonas aeruginosa are prevalent cystic fibrosis pathogens, and infection with both is associated with worse outcomes. These organisms have evolved mechanisms of competing with one another. For example, P. aeruginosa produces pyocyanin, which inhibits S. aureus growth. Our research has identified how pyocyanin inhibits S. aureus growth and how S. aureus can adapt to survive in the presence of pyocyanin. Understanding how S. aureus sustains infection in the presence of P. aeruginosa may identify means of disrupting these microbial communities.

The full control of positional selectivity is of prime importance in C–H activation technology. Chelation assistance served as the stimulus for the development of a plethora of ortho-selective arene functionalizations. In sharp contrast, meta-selective C–H functionalizations continue to be scarce, with all ruthenium-catalysed transformations currently requiring difficult to remove or modify nitrogen-containing heterocycles. Herein, we describe a unifying concept to access a wealth of meta-decorated arenes by a unique arene ligand effect in proximity-induced ruthenium(II) C–H activation catalysis. The transformative nature of our strategy is mirrored by providing a step-economical entry to a range of meta-substituted arenes, including ketones, acids, amines and phenols—key structural motifs in crop protection, material sciences, medicinal chemistry and pharmaceutical industries., While ortho-selective C-H activation is well explored, general meta-selective methods are rare and often require directing groups that are retained in the final products. Here the authors show that transient imine groups can be used to direct the meta-functionalization of a range of arenes.