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Efficient and site‐specific delivery of therapeutics drugs remains a critical challenge in cancer treatment. Traditional drug nanocarriers such as antibody‐drug conjugates are not generally accessible due to their high cost and can lead to serious side effects including life‐threatening allergic reactions. Here, these problems are overcome via the engineering of supramolecular agents that are manufactured with an innovative double imprinting approach. The developed molecularly imprinted nanoparticles (nanoMIPs) are targeted toward a linear epitope of estrogen receptor alfa (ERα) and loaded with the chemotherapeutic drug doxorubicin. These nanoMIPs are cost‐effective and rival the affinity of commercial antibodies for ERα. Upon specific binding of the materials to ERα, which is overexpressed in most breast cancers (BCs), nuclear drug delivery is achieved via receptor‐mediated endocytosis. Consequentially, significantly enhanced cytotoxicity is elicited in BC cell lines overexpressing ERα, paving the way for precision treatment of BC. Proof‐of‐concept for the clinical use of the nanoMIPs is provided by evaluating their drug efficacy in sophisticated three‐dimensional (3D) cancer models, which capture the complexity of the tumor microenvironment in vivo without requiring animal models. Thus, these findings highlight the potential of nanoMIPs as a promising class of novel drug compounds for use in cancer treatment. [ABSTRACT FROM AUTHOR]

In the ever‐growing demand for sustainable ways to produce high‐value small molecules, biocatalysis has come to the forefront of greener routes to these chemicals. As such, the need to constantly find and optimise suitable biocatalysts for specific transformations has never been greater. Metagenome mining has been shown to rapidly expand the toolkit of promiscuous enzymes needed for new transformations, without requiring protein engineering steps. If protein engineering is needed, the metagenomic candidate can often provide a better starting point for engineering than a previously discovered enzyme on the open database or from literature, for instance. In this review, we highlight where metagenomics has made substantial impact on the area of biocatalysis in recent years. We review the discovery of enzymes in previously unexplored or 'hidden' sequence space, leading to the characterisation of enzymes with enhanced properties that originate from natural selection pressures in native environments. [ABSTRACT FROM AUTHOR]

Reductive aminases (RedAms) have recently emerged as promising biocatalysts for the synthesis of chiral secondary amines by coupling primary amines with aldehydes/ketones. However, access to tertiary amines remains more problematic, particularly when coupling ketones with secondary amines. Here we show that the scope of these enzymes can be extended to allow selective reductive aminations of cyclic secondary amines, such as piperidines and morpholines, with both aldehydes and ketones. These biotransformations provide access to important motifs found in active pharmaceutical ingredients and other bioactive molecules. RedAm‐361, discovered from a metagenomic library, was engineered via directed evolution to allow efficient coupling of cyclic amines with carbonyl partners, including dynamic kinetic resolutions of α‐functionalized aldehydes and enantioselective amination of ketones. These RedAms now serve as valuable scaffolds for the engineering of industrial biocatalysts to produce key pharmaceutical intermediates. [ABSTRACT FROM AUTHOR]

Virus recognition has been driven to the forefront of molecular recognition research due to the COVID‐19 pandemic. Development of highly sensitive recognition elements, both natural and synthetic is critical to facing such a global issue. However, as viruses mutate, it is possible for their recognition to wane through changes in the target substrate, which can lead to detection avoidance and increased false negatives. Likewise, the ability to detect specific variants is of great interest for clinical analysis of all viruses. Here, a hybrid aptamer‐molecularly imprinted polymer (aptaMIP), that maintains selective recognition for the spike protein template across various mutations, while improving performance over individual aptamer or MIP components (which themselves demonstrate excellent performance). The aptaMIP exhibits an equilibrium dissociation constant of 1.61 nM toward its template which matches or exceeds published examples of imprinting of the spike protein. The work here demonstrates that "fixing" the aptamer within a polymeric scaffold increases its capability to selectivity recognize its original target and points toward a methodology that will allow variant selective molecular recognition with exceptional affinity. [ABSTRACT FROM AUTHOR]

In 2017, two companies, Novartis AG and Syngenta AG, joined forces with the group of Prof. Buller, head of the Competence Center for Biocatalysis (CCBIO), to tackle the challenge of enzymatic late‐stage halogenation. This biocatalytic method was considered to provide a more sustainable approach to late‐stage halogenation of complex molecules than traditional synthetic approaches. Using machine‐learning guided protein engineering, α‐ketoglutarate dependent halogenases were evolved into versatile catalysts capable of selectively chlorinating inactivated C−H bonds. Structurally diverse molecules, namely an analogue of martinelline as well as two members of the soraphen natural product family, were enzymatically chlorinated at two distinct positions in a regio‐ and stereoselective manner, thus demonstrating the synthetic usefulness of such a strategy. As part of our three‐year collaboration, flavin‐dependent halogenases were also studied. [ABSTRACT FROM AUTHOR]

Allergy assessments and penicillin skin testing are associated with reductions in high‐Clostridioides difficile infection (CDI)‐risk antibiotic use and lower hospital‐acquired CDI rates; however, these activities require substantial personnel and resource allocation. Recently, many antimicrobial stewardship programs' (ASPs) focus shifted towards supporting the COVID‐19 pandemic response. We evaluated the impact of the COVID‐19 pandemic on a pharmacist‐led allergy assessment and penicillin skin testing program. Patients undergoing allergy assessment and/or penicillin skin testing (PST) from 1 January 2017 through 30 April 2021 were included for review. Monthly PST and allergy assessment rates were calculated and defined as the number of PSTs or allergy assessments per 1000 unique patient encounters for each month, respectively. The study used interrupted time series regression to assess potential level and slope changes in allergy assessments and PSTs during the pandemic. 200 058 total inpatient encounters by 188 867 unique patients occurred during the study period. ASP performed 918 allergy assessments and 204 PSTs. The local onset of the SARS‐CoV‐2 pandemic during March 2020 was associated with significant level reductions in allergy assessments and PSTs. Additional responsibilities added to the ASP team during the COVID‐19 pandemic limited the ability to perform core antimicrobial stewardship activities with proven patient care benefits. [ABSTRACT FROM AUTHOR]

N‐alkanoyl‐N‐methylglucamides (MEGAs) are non‐toxic surfactants widely used as commercial ingredients, but more sustainable syntheses towards these compounds are highly desirable. Here, we present a biocatalytic route towards MEGAs and analogues using a truncated carboxylic acid reductase construct tailored for amide bond formation (CARmm‐A). CARmm‐A is capable of selective amide bond formation without the competing esterification reaction observed in lipase catalysed reactions. A kinase was implemented to regenerate ATP from polyphosphate and by thorough reaction optimisation using design of experiments, the amine concentration needed for amidation was significantly reduced. The wide substrate scope of CARmm‐A was exemplified by the synthesis of 24 commercially relevant amides, including selected examples on a preparative scale. This work establishes acyl‐phosphate mediated chemistry as a highly selective strategy for biocatalytic amide bond formation in the presence of multiple competing alcohol functionalities. [ABSTRACT FROM AUTHOR]

The direct asymmetric reductive amination of heteroaryl ketones has been a long‐standing synthetic challenge. Here we report the engineering of an amine dehydrogenase (AmDH) from Jeotgalicoccus aerolatus for the asymmetric synthesis of chiral α‐(hetero)aryl primary amines in excellent conversions (up to 99 %) and enantioselectivities (up to 99 % ee). The best AmDH variant (Ja‐AmDH‐M33) exhibited high activity and specificity toward alkyl (hetero)aryl ketones, even for those bearing a bulky alkyl chain. An efficient directed evolution approach based on molecular docking was implemented to enlarge the active pocket with a more hydrophobic entrance, which is responsible for the high activity. The Ja‐AmDH‐M33 was also used for preparative‐scale synthesis of pharmaceutically relevant amines and a key intermediate of chiral pincer ligands, which highlighted its practical application in synthetic chemistry. [ABSTRACT FROM AUTHOR]

Test-guided dietary exclusions for treating established atopic dermatitis in children: A systematic review Meanwhile, as per NICE guidance, food allergy tests should be interpreted in the context of childen's symptoms where IgE-mediated allergy is suspected and allergy-focused clinical history should guide dietary exclusion and reintroduction advice in suspected non-IgE food allergy. TEST (Trial of Eczema allergy Screening Tests): protocol for feasibility randomised controlled trial of allergy tests in children with eczema, including economic scoping and nested qualitative study. Food allergy tests are sometimes used to guide dietary exclusions for eczema symptoms. [Extracted from the article]

Electron‐rich phenolic substrates can be derived from the depolymerisation of lignin feedstocks. Direct biotransformations of the hydroxycinnamic acid monomers obtained can be exploited to produce high‐value chemicals, such as α‐amino acids, however the reaction is often hampered by the chemical autooxidation in alkaline or harsh reaction media. Regioselective O‐methyltransferases (OMTs) are ubiquitous enzymes in natural secondary metabolic pathways utilising an expensive co‐substrate S‐adenosyl‐l‐methionine (SAM) as the methylating reagent altering the physicochemical properties of the hydroxycinnamic acids. In this study, we engineered an OMT to accept a variety of electron‐rich phenolic substrates, modified a commercial E. coli strain BL21 (DE3) to regenerate SAM in vivo, and combined it with an engineered ammonia lyase to partake in a one‐pot, two whole cell enzyme cascade to produce the l‐DOPA precursor l‐veratrylglycine from lignin‐derived ferulic acid. [ABSTRACT FROM AUTHOR]

2‐Aminotetralin and 3‐aminochroman derivatives are key structural motifs present in a wide range of pharmaceutically important molecules. Herein, we report an effective biocatalytic approach towards these molecules through the enantioselective reductive coupling of 2‐tetralones and 3‐chromanones with a diverse range of primary amine partners. Metagenomic imine reductases (IREDs) were employed as the biocatalysts, obtaining high yields and enantiocomplementary selectivity for >15 examples at preparative scale, including the precursors to Ebalzotan, Robalzotan, Alnespirone and 5‐OH‐DPAT. We also present a convergent chemo‐enzymatic total synthesis of the Parkinson's disease therapy Rotigotine in 63 % overall yield and 92 % ee. [ABSTRACT FROM AUTHOR]

Summary: Bimetallic nanoparticle catalysts have attracted considerable attention due to their unique chemical and physical properties. The ability of metal‐reducing bacteria to produce highly catalytically active monometallic nanoparticles is well known; however, the properties and catalytic activity of bimetallic nanoparticles synthesized with these organisms is not well understood. Here, we report the one‐pot biosynthesis of Pd/Ag (bio‐Pd/Ag) and Pd/Au (bio‐Pd/Au) nanoparticles using the metal‐reducing bacterium, Shewanella oneidensis, under mild conditions. Energy dispersive X‐ray analyses performed using scanning transmission electron microscopy (STEM) revealed the presence of both metals (Pd/Ag or Pd/Au) in the biosynthesized nanoparticles. X‐ray absorption near‐edge spectroscopy (XANES) suggested a significant contribution from Pd(0) and Pd(II) in both bio‐Pd/Ag and bio‐Pd/Au, with Ag and Au existing predominately as their metallic forms. Extended X‐ray absorption fine‐structure spectroscopy (EXAFS) supported the presence of multiple Pd species in bio‐Pd/Ag and bio‐Pd/Au, as inferred from Pd–Pd, Pd–O and Pd–S shells. Both bio‐Pd/Ag and bio‐Pd/Au demonstrated greatly enhanced catalytic activity towards Suzuki–Miyaura cross‐coupling compared to a monometallic Pd catalyst, with bio‐Pd/Ag significantly outperforming the others. The catalysts were very versatile, tolerating a wide range of substituents. This work demonstrates a green synthesis method for novel bimetallic nanoparticles that display significantly enhanced catalytic activity compared to their monometallic counterparts. [ABSTRACT FROM AUTHOR]

A key aim of biocatalysis is to mimic the ability of eukaryotic cells to carry out multistep cascades in a controlled and selective way. As biocatalytic cascades get more complex, reactions become unattainable under typical batch conditions. Here a number of continuous flow systems were used to overcome batch incompatibility, thus allowing for successful biocatalytic cascades. As proof‐of‐principle, reactive carbonyl intermediates were generated in situ using alcohol oxidases, then passed directly to a series of packed‐bed modules containing different aminating biocatalysts which accordingly produced a range of structurally distinct amines. The method was expanded to employ a batch incompatible sequential amination cascade via an oxidase/transaminase/imine reductase sequence, introducing different amine reagents at each step without cross‐reactivity. The combined approaches allowed for the biocatalytic synthesis of the natural product 4O‐methylnorbelladine. [ABSTRACT FROM AUTHOR]

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Enzyme catalysis is gaining increasing importance in synthetic chemistry. Nowadays, the growing number of biocatalysts accessible by means of bioinformatics and enzyme engineering opens up an immense variety of selective reactions. Biocatalysis especially provides excellent opportunities for late‐stage modification often superior to conventional de novo synthesis. Enzymes have proven to be useful for direct introduction of functional groups into complex scaffolds, as well as for rapid diversification of compound libraries. Particularly important and highly topical are enzyme‐catalysed oxyfunctionalisations, halogenations, methylations, reductions, and amide bond formations due to the high prevalence of these motifs in pharmaceuticals. This Review gives an overview of the strengths and limitations of enzymatic late‐stage modifications using native and engineered enzymes in synthesis while focusing on important examples in drug development. [ABSTRACT FROM AUTHOR]

N‐Substituted α‐amino esters are widely used as chiral intermediates in a range of pharmaceuticals. Here we report the enantioselective biocatalyic synthesis of N‐substituted α‐amino esters through the direct reductive coupling of α‐ketoesters and amines employing sequence diverse metagenomic imine reductases (IREDs). Both enantiomers of N‐substituted α‐amino esters were obtained with high conversion and excellent enantioselectivity under mild reaction conditions. In addition >20 different preparative scale transformations were performed highlighting the scalability of this system. [ABSTRACT FROM AUTHOR]

Background: Parents commonly ask about food allergy tests, to find a cause for their child's eczema, yet the value of routine testing is uncertain. Objective: To determine whether a clinical trial comparing test‐guided dietary advice versus usual care, for the management of eczema, is feasible. Methods: Children (>3 months and <5 years) with mild‐to‐severe eczema, recruited via primary care, were individually randomized (1:1) to intervention or usual care. Intervention participants underwent structured allergy history and skin prick tests (SPT) with dietary advice for cow's milk, hen's egg, wheat, peanut, cashew and codfish. All participants were followed up for 24 weeks. A sample of doctors and parents was interviewed. Registration ISRCTN15397185. Results: From 1059 invitation letters sent to carers of potentially eligible children, 84 were randomized (42 per group) with mean age of 32.4 months (SD 13.9) and POEM of 8.7 (4.8). Of the 42, 6 (14%) intervention participants were advised to exclude one or more foods, most commonly egg, peanut or milk. By participant, 1/6 had an oral food challenge (negative); 3/6 were told to exclude until review in allergy clinic; and 6/6 advised a home dietary trial (exclusion and reintroduction of food over 4–6 weeks) – with 1/6 partially completing it. Participant retention (four withdrawals) and data completeness (74%–100%) were acceptable and contamination low (two usual care participants had allergy tests). There were three minor SPT‐related adverse events. During follow‐up, 12 intervention and 8 usual care participants had minor, unrelated adverse events plus one unrelated hospital admission. Conclusions: It is possible to recruit, randomize and retain children with eczema from primary care into a trial of food allergy screening and to collect the outcomes of interest. Changes to recruitment and inclusion criteria are needed in a definitive trial, to ensure inclusion of younger children from more diverse backgrounds. [ABSTRACT FROM AUTHOR]

The integration of electro and bio‐catalysis offers new ways of making molecules under very mild, environmentally benign conditions. We show that TEMPO mediated electro‐catalytic oxidation of alcohols can be adapted to work in aqueous buffers, with minimal organic co‐solvent, enabling integration with biocatalytic reductive amination using the AdRedAm enzyme. The combined process offers a new approach to amine alkylation with native alcohols, a key bond formation in the chemical economy that is currently achieved via precious metal‐catalyzed hydrogen‐borrowing technologies. The electrobio transformation is effective for primary and secondary alcohols undergoing coupling with allyl, propargyl, benzyl, and cyclopropyl amines, and has been adapted for use with solid‐supported AdRedAm for ease of operation. [ABSTRACT FROM AUTHOR]

Enantiomerically enriched chiral secondary alcohols serve as valuable building blocks for drug intermediates and fine chemicals. In this study the deracemisation of secondary alcohols to generate enantiomeric pure chiral alcohols has been achieved by combining enantio‐selective enzymatic oxidation of a secondary alcohol, by a variant of GOase (GOase M3‐5), with either non‐selective ketone reduction via transfer hydrogenation (TH) or enantio‐selective asymmetric transfer hydrogenation (ATH). Both the enzymatic oxidation system and the transition‐metal mediated reduction system were optimised to ensure compatibility with each other resulting in a homogeneous reaction system. 1‐(4‐nitrophenyl)ethanol was generated with 99 % conversion and 98 % ee by the deracemisation method, and it has been extended to a series of other secondary alcohols with comparable results. [ABSTRACT FROM AUTHOR]

Biocatalysis has the potential to enable green chemistry. New methods of enzyme immobilisation will be required to improve enzyme stability, product purification, and compatibility of different enzymes in the same reaction conditions. Deoxyribonucleic acid (DNA) stands out among supramolecular scaffolds, as simple Watson–Crick base‐pairing rules can be used to rationally design a unique nanoscale environment around each individual enzyme in a cascade. Enhancements of enzyme activity and stability on DNA nanostructures have previously been reported, but never in the context of industrially relevant chemical syntheses or reaction conditions. Here, the authors show DNA can enhance the activity and stability of a galactose oxidase mutant, which could be used in a cascade to produce bioplastics from lignin. The enzyme was enhanced in the cell‐free extract, which to their knowledge has not been shown before for any enzymes on DNA. This is significant because crude biocatalytic reactions are vastly more cost‐effective. This opens the door to further work on multienzyme cascades by tuning the properties of individual enzymes. [ABSTRACT FROM AUTHOR]

The combination of biocatalysis and chemo‐catalysis increasingly offers chemists access to more diverse chemical architectures. Here, we describe the combination of a toolbox of chiral‐amine‐producing biocatalysts with a Buchwald–Hartwig cross‐coupling reaction, affording a variety of α‐chiral aniline derivatives. The use of a surfactant allowed reactions to be performed sequentially in the same flask, preventing the palladium catalyst from being inhibited by the high concentrations of ammonia, salts, or buffers present in the aqueous media in most cases. The methodology was further extended by combining with a dual‐enzyme biocatalytic hydrogen‐borrowing cascade in one pot to allow for the conversion of a racemic alcohol to a chiral aniline. [ABSTRACT FROM AUTHOR]

The conversion of carboxylic acids, such as acrylic acids, to amines is a transformation that remains challenging in synthetic organic chemistry. Despite the ubiquity of similar moieties in natural metabolic pathways, biocatalytic routes seem to have been overlooked for this purpose. Herein we present the conception and optimisation of a two‐enzyme system, allowing the synthesis of β‐phenylethylamine derivatives from readily‐available ring‐substituted cinnamic acids. After characterisation of both parts of the reaction in a two‐step approach, a set of conditions allowing the one‐pot biotransformation was optimised. This combination of a reversible deaminating and irreversible decarboxylating enzyme, both specific for the amino acid intermediate in tandem, represents a general method by which new strategies for the conversion of carboxylic acids to amines could be designed. [ABSTRACT FROM AUTHOR]

In living cells, the overall rates of catalytic reaction chains (cascades) are massively enhanced by nanoconfinement of enzymes in tiny enclosed volumes: presented in such a way, interdependent catalysts are highly concentrated, and distances (active site‐to‐active site) across which intermediates and cofactors must diffuse, may be tiny. In a parallel technology exploiting this principle, enzyme cascades are powered, amplified, and monitored in real time as they work in concert, being nanoconfined within the pores of an electrically conductive metal oxide electrode. The technology, nicknamed the electrochemical leaf, mimics chloroplast biosynthesis by exploiting nicotinamide adenine dinucleotide (NADP(H)) recycling catalysed by the flavoenzyme, ferredoxin NADP+ reductase (FNR). Adsorbed on the inner walls of the nanopores, FNR rapidly transfers electrons between the electrode and NADP(H). This activity is coupled to an oxidoreductase enzyme, also nanoconfined within the pores, which recycles the cofactor and selectively synthesises a desired product or senses an analyte. Use of catalyst and cofactor is very efficient. The technology is simple, inexpensive and adaptable, and scalable to both microscopic levels (diagnostics) and macroscopic levels (organic synthesis). Whereas native FNR is specific for NADP(H), the technology can be extended by genetic engineering to include NAD(H) as recycling cofactor. [ABSTRACT FROM AUTHOR]

Pertuzumab and trastuzumab are monoclonal antibody inhibitors targeting human epidermal growth factor receptor 2 (HER‐2) and are increasingly being utilised in the management of HER2‐positive breast cancer, having been demonstrated to improve progression‐free survival in conjunction with docetaxel. We present a rare presentation of a lichenoid drug eruption, in an annular atrophic variant, in a 35‐year‐old woman after initiation of HER2‐inhibitor (pertuzumab and trastuzumab) therapy for metastatic breast cancer. [ABSTRACT FROM AUTHOR]

No Abstract [ABSTRACT FROM AUTHOR]

Copyright of Angewandte Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In living cells, redox chains rely on nanoconfinement using tiny enclosures, such as the mitochondrial matrix or chloroplast stroma, to concentrate enzymes and limit distances that nicotinamide cofactors and other metabolites must diffuse. In a chemical analogue exploiting this principle, nicotinamide adenine dinucleotide phosphate (NADPH) and NADP+ are cycled rapidly between ferredoxin–NADP+ reductase and a second enzyme—the pairs being juxtaposed within the 5–100 nm scale pores of an indium tin oxide electrode. The resulting electrode material, denoted (FNR+E2)@ITO/support, can drive and exploit a potentially large number of enzyme‐catalysed reactions. In close quarters: Nicotinamide adenine dinucleotide phosphate (NADPH) and NADP+ are cycled rapidly between ferredoxin–NADP+ reductase (FNR) and a dehydrogenase enzyme (E2) within the 5–100 nm pores of an indium tin oxide electrode. The electrode mimics the nanoconfinement strategies of natural systems, such as the chloroplast stroma or mitochondria in living cells. [ABSTRACT FROM AUTHOR]

Herein we report the biocatalytic synthesis of substituted pyrazines and pyrroles using a transaminase (ATA) to mediate the key amination step of the ketone precursors. Treatment of α‐diketones with ATA‐113 in the presence of a suitable amine donor yielded the corresponding α‐amino ketones which underwent oxidative dimerization to the pyrazines. Selective amination of α‐diketones in the presence of β‐keto esters afforded substituted pyrroles in a biocatalytic equivalent of the classical Knorr pyrrole synthesis. Finally we have shown that pyrroles can be prepared by internal amine transfer catalyzed by a transaminase in which no external amine donor is required. The key amination step of the ketone precursors in a biocatalytic synthesis of substituted pyrazines and pyrroles is mediated using a transaminase (ATA). Treatment of α‐diketones with ATA‐113 in the presence of an amine donor yielded α‐amino ketones which underwent oxidative dimerization to the pyrazines. Selective amination of α‐diketones in the presence of β‐keto esters afforded substituted pyrroles in a biocatalytic equivalent of the classical Knorr pyrrole synthesis. [ABSTRACT FROM AUTHOR]

The Chemical Response to Oil Spill: Ecological Effects Research Forum's water accommodated fraction procedure was compared with 2 alternative techniques in which crude oil was passively dosed from silicone tubing or O‐rings. Fresh Macondo oil (MC252) was dosed at 30 mg/L using each approach to investigate oil dissolution kinetics, which was monitored by fluorometry as estimated oil equivalents (EOEs). Subsequent experiments with each dosing method were then conducted at multiple oil loadings. Following equilibration, test media were analytically characterized for polyaromatic hydrocarbons (PAHs) using gas chromatography (GC)–mass spectrometry and dissolved oil using biomimetic solid‐phase microextraction (SPME). The results showed that equilibrium was achieved within 72 h for all methods. Measured PAH concentrations were compared with oil solubility model predictions of dissolved exposures. The concentration and composition of measured and predicted dissolved PAHs varied with oil loading and were consistent between dosing methods. Two‐dimensional GC compositional data for this oil were then used to calculate dissolved toxic units for predicting MC252 oil acute toxicity across the expected range of species sensitivities. Predicted toxic units were nonlinear with loading and correlated to both EOE and biomimetic SPME. Passive dosing methods provide a practical strategy to deliver and maintain dissolved oil concentrations while avoiding the complicating role that droplets can introduce in exposure characterization and test interpretation. Environ Toxicol Chem 2018;37:2810–2819. © 2018 SETAC [ABSTRACT FROM AUTHOR]

Background: COVID‐19 restrictions have been associated with apathy, anxiety and depression in individuals with cognitive impairment1‐3 and increased stress in caregivers4. But despite links between these restrictions and sleep impairment in the general population5, effects on sleep in this cohort are not widely reported. Here we determine overall sleep quality in these populations during the first UK lockdown, how this changed over time and explanatory factors associated with longitudinal change. Method: Cognitively impaired group (CIG), carer group (CG) and older healthy participants completed online self‐reported validated questionnaires (PSQI, GAD‐7, PHQ‐8 and DBAS) alongside bespoke questions comprising the 'SleepQuest' study at two comparable stringent lockdown periods within the UK [t1 – (29/4/20‐13/5/20) and t2 – (5/11/20‐2/12/20)]. Analysis utilised paired t‐tests with Bonferroni correction with 95% confidence intervals. Multivariable linear regression evaluated predictive factors. Result: Within the CIG, baseline n = 79 [MCI, n = 33; AD, n = 19; Other, n = 27], mean age 68.7±9.7, with follow‐up data for n = 37. Within the CG, baseline n = 183, mean age 59.4±11.1, follow‐up n = 116. Overall sleep quality by PSQI Total was impaired at baseline (CIG = 7.8±4.3; CG = 7.9±4.0) compared to 6.6±3.6 for older healthy participants (n = 2354). There was a trend towards sleep quality deterioration from t1‐t2 in both groups (CIG ‐ Mean diff = 0.84, CI[‐0.20,1.84], p = 0.111; CG ‐ Mean diff = 0.51, CI[‐0.01,1.02], p = 0.053). PSQI subcomponent analysis revealed increasing sleep medication use in both groups (CIG – Mean diff = 0.83, CI[0.36,1.32], pcorr = 0.007; CG – Mean diff = 0.99, CI[0.81,1.17], pcorr<0.001). However, levels of daytime dysfunction improved in both groups (CIG – Mean diff = ‐0.54, CI[‐0.87,‐0.21], pcorr = 0.014; CG – Mean diff = ‐0.46, CI[‐0.61,‐0.30], pcorr<0.001). Within the CIG, affective and behavioural factors at t1 did not predict sleep at t2. Within carers, increased anxiety (total GAD‐7) at t1 predicted worse sleep at t2 (Est[normalised PSQI total] = 0.22, SE = 0.10, p = 0.041). Conclusion: Overall sleep quality for individuals with cognitive impairment and their carers was poor at baseline and trended towards further deterioration, although daytime function improved. Within this cohort, potential compensatory strategies included increased use of sleep medication (associated with adverse outcomes). Given impaired sleep may accelerate progression of dementia neuropathology6,7, it is important to understand and ameliorate the impact of prolonged socio‐political stressors on people with dementia and their carers. [ABSTRACT FROM AUTHOR]

A multi‐enzymatic cascade process involving transaminases (TAs) and reductive aminases (RedAms) to produce enantiomerically pure 2,5‐disubstituted pyrrolidine alkaloids from their respective 1,4‐diketones is reported. Several TAs were screened and the best results for diketone monoamination were obtained with an R‐selective TA from Mycobacterium chlorophenicum and with an S‐selective TA from Bacillus megaterium. Pyrroline reduction was best performed by a reductive aminase from Ajellomyces dermatitidis (AdRedAm). Finally, a biocatalytic one‐pot cascade was implemented using the aforementioned enzymes and a variety of 2‐methyl‐5‐alkylpyrrolidines were produced with high (>99 %) conversion, diastereomeric and enantiomeric excess values. Cascades get antsy! A one‐pot enzymatic cascade using transaminase and reductive aminase biocatalysts has been successfully implemented for the regio‐ and stereoselective synthesis of a panel of 2‐methyl‐5‐alkylpyrrolidines from the corresponding 1,4‐diketones. [ABSTRACT FROM AUTHOR]

Abstract: We report a simple, mild, and synthetically clean approach to accelerate the rate of enzymatic oxidation reactions by a factor of up to 100 when compared to conventional batch gas/liquid systems. Biocatalytic decomposition of H2O2 is used to produce a soluble source of O2 directly in reaction media, thereby enabling the concentration of aqueous O2 to be increased beyond equilibrium solubility under safe and practical conditions. To best exploit this method, a novel flow reactor was developed to maximize productivity (g product L−1 h−1). This scalable benchtop method provides a distinct advantage over conventional bio‐oxidation in that no pressurized gas or specialist equipment is employed. The method is general across different oxidase enzymes and compatible with a variety of functional groups. These results culminate in record space‐time yields for bio‐oxidation. [ABSTRACT FROM AUTHOR]

Abstract: Cyclic ketones bearing α‐quaternary stereocenters underwent efficient kinetic resolution using cyclohexanone monooxygenase (CHMO) from Acinetobacter calcoaceticus. Lactones possessing tetrasubstituted stereocenters were obtained with high enantioselectivity (up to >99 % ee) and complete chemoselectivity. Preparative‐scale biotransformations were exploited in conjunction with a SmI2‐mediated cyclization process to access complex, enantiomerically enriched cycloheptan‐ and cycloctan‐1,4‐diols. In a parallel approach to structurally distinct products, enantiomerically enriched ketones from the resolution with an α‐quaternary stereocenter were used in a SmI2‐mediated cyclization process to give cyclobutanol products (up to >99 % ee). [ABSTRACT FROM AUTHOR]

Abstract: The ability of cytochrome P450 monooxygenases to catalyse a wide variety of synthetically challenging C−H activation reactions makes them highly desirable biocatalysts both for the synthesis of chiral intermediates and for late‐stage functionalisations. However, P450s are plagued by issues associated with poor expression, solubility and stability. Catalytically self‐sufficient P450s, in which the haem and reductase domains are fused in a single protein, obviate the need for additional redox partners and are attractive as biocatalysts. Here we present a panel of natural self‐sufficient P450s from thermophilic organisms (CYP116B65 from A. thermoflava, CYP116B64 from A. xiamenense, CYP116B63 from J. thermophila, CYP116B29 from T. bispora and CYP116B46 from T. thermophilus). These P450s display enhanced expression and stability over their mesophilic homologues. Activity profiling of these enzymes revealed that each P450 displayed a different fingerprint in terms of substrate range and reactivity that cover reactions as diverse as hydroxylation, demethylation, epoxidation and sulfoxidation. The productivity of the bio‐transformation of diclofenac to produce the 5‐hydroxy metabolite increased 42‐fold using the thermostable P450‐AX (>0.5 g L−1 h−1) compared to the P450‐RhF system reported previously. In conclusion, we have generated a toolkit of thermostable self‐sufficient P450 biocatalysts with a broad substrate range and reactivity. [ABSTRACT FROM AUTHOR]

Abstract: The NADP(H)‐dependent reductive aminase from Aspergillus oryzae (AspRedAm) was combined with an NADPH oxidase (NOX) to develop a redox system that recycles the co‐factor. The AspRedAm‐NOX system was applied initially for the kinetic resolution of a variety of racemic secondary and primary amines to yield S‐configured amines with enantiomeric excess (ee) values up to 99 %. The addition of ammonia borane to this system enabled the efficient deracemization of racemic amines, including the pharmaceutical drug rasagiline and the natural product salsolidine, with conversions up to >98 % and >99 % ee Furthermore, by using the AspRedAm W210A variant it was possible to generate the opposite R enantiomers with efficiency comparable to, or even better than, the wildtype AspRedAm. [ABSTRACT FROM AUTHOR]

Abstract: Reductive amination of carbonyl compounds constitutes one of the most efficient ways to rapidly construct chiral and achiral amine frameworks. Imine reductase (IRED) biocatalysts represent a versatile family of enzymes for amine synthesis through NADPH‐mediated imine reduction. The reductive aminases (RedAms) are a subfamily of IREDs that were recently shown to catalyze imine formation as well as imine reduction. Herein, a diverse library of novel enzymes were expressed and screened as cell‐free lysates for their ability to facilitate reductive amination to expand the known suite of biocatalysts for this transformation and to identify more enzymes with potential industrial applications. A range of ketones and amines were examined, and enzymes were identified that were capable of accepting benzylamine, pyrrolidine, ammonia, and aniline. Amine equivalents as low as 2.5 were employed to afford up to >99 % conversion, and for chiral products, up to >98 % ee could be achieved. Preparative‐scale reactions were conducted with low amine equivalents (1.5 or 2.0) of methylamine, allylamine, and pyrrolidine, achieving up to >99 % conversion and 76 % yield. [ABSTRACT FROM AUTHOR]

Abstract: d‐Phenylalanine derivatives are valuable chiral building blocks for a wide range of pharmaceuticals. Here, we developed stereoinversion and deracemization biocatalytic cascades to synthesize d‐phenylalanine derivatives that contain electron‐donating or ‐withdrawing substituents of various sizes and at different positions on the phenyl ring with a high enantiomeric excess (90 to >99 % ee) from commercially available racemic mixtures or l‐amino acids. These whole‐cell systems couple Proteus mirabilis l‐amino acid deaminase with an engineered aminotransferase that displays native‐like activity towards d‐phenylalanine, which we generated from Bacillus sp. YM‐1 d‐amino acid aminotransferase. Our cascades are applicable to preparative‐scale synthesis and do not require cofactor‐regeneration systems or chemical reducing agents. [ABSTRACT FROM AUTHOR]

Abstract: Naturally occurring isoprenoid quinones mediate electron transfer in respiratory or photosynthetic chains of living organisms. Tremendous progress has been made in the elucidation of biosynthetic pathways of prenylated quinones and a number of enzymes that catalyze specific transformation steps with remarkably high regio‐ and stereoselectivity have been characterized. Interestingly, some of these enzymes possess broad substrate scope towards synthetic analogues, thereby enabling their application as synthetic tools. The availability of mechanistic, structural and mutagenesis information for many of the pathway enzymes presents opportunities for protein engineering, a powerful approach that may improve the suitability of these biocatalysts for industrial processes. [ABSTRACT FROM AUTHOR]

There are few studies that have evaluated hydrocarbon toxicity to vertically migrating deep-sea micronekton. Crustaceans were collected alive using a 9-m2 Tucker trawl with a thermally insulated cod end and returned to the laboratory in 10 °C seawater. Toxicity of the polycyclic aromatic hydrocarbon 1-methylnaphthalene to Americamysis bahia, Janicella spinacauda, Systellaspis debilis, Sergestes sp., Sergia sp., and a euphausiid species was assessed in a constant exposure toxicity test utilizing a novel passive dosing toxicity testing protocol. The endpoint of the median lethal concentration tests was mortality, and the results revealed high sensitivity of the deep-sea micronekton compared with other species for which these data are available. Threshold concentrations were also used to calculate critical target lipid body burdens using the target lipid model. Environ Toxicol Chem 2017;36:3415-3423. © 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC [ABSTRACT FROM AUTHOR]

Biocatalytic retrosynthetic analysis of dibenz[c,e]azepines has highlighted the use of imine reductase (IRED) and ω-transaminase (ω-TA) biocatalysts to establish the key stereocentres of these molecules. Several enantiocomplementary IREDs were identified for the synthesis of ( R)- and ( S)-5-methyl-6,7-dihydro-5 H-dibenz[c,e]azepine with excellent enantioselectivity, by reduction of the parent imines. Crystallographic evidence suggests that IREDs may be able to bind one conformer of the imine substrate such that, upon reduction, the major product conformer is generated directly. ω-TA biocatalysts were also successfully employed for the production of enantiopure 1-(2-bromophenyl)ethan-1-amine, thus enabling an orthogonal route for the installation of chirality into dibenz[c,e]azepine framework. [ABSTRACT FROM AUTHOR]

Carboxylic acid reductases (CARs) catalyze the reduction of a broad range of carboxylic acids to aldehydes using the cofactors adenosine triphosphate and nicotinamide adenine dinucleotide phosphate, and have become attractive biocatalysts for organic synthesis. Mechanistic understanding of CARs was used to expand reaction scope, generating biocatalysts for amide bond formation from carboxylic acid and amine. CARs demonstrated amidation activity for various acids and amines. Optimization of reaction conditions, with respect to pH and temperature, allowed for the synthesis of the anticonvulsant ilepcimide with up to 96 % conversion. Mechanistic studies using site-directed mutagenesis suggest that, following initial enzymatic adenylation of substrates, amidation of the carboxylic acid proceeds by direct reaction of the acyl adenylate with amine nucleophiles. [ABSTRACT FROM AUTHOR]

The NADPH-dependent secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicus (TeSADH), displaying broad substrate specificity and low enantioselectivity, was engineered to accept NADH as a cofactor. The engineered TeSADH showed a >10 000-fold switch from NADPH towards NADH compared to the wildtype enzyme. This TeSADH variant was applied to a biocatalytic hydrogen-borrowing system that employed catalytic amounts of NAD+, ammonia, and an amine dehydrogenase, which thereby enabled the conversion a range of alcohols into chiral amines. [ABSTRACT FROM AUTHOR]

The chemical synthesis of ketoisophorone, a valuable building block of vitamins and pharmaceuticals, suffers from several drawbacks in terms of reaction conditions and selectivity. Herein, the first biocatalytic one-pot double oxidation of the readily available α-isophorone to ketoisophorone is described. Variants of the self-sufficient P450cam-RhFRed with improved activity have been identified to perform the first step of the designed cascade (regio- and enantioselective allylic oxidation of α-isophorone to 4-hydroxy-α-isophorone). For the second step, the screening of a broad panel of alcohol dehydrogenases (ADHs) led to the identification of Cm-ADH10 from Candida magnoliae. The crystal structure of Cm-ADH10 was solved and docking experiments confirmed the preferred position and geometry of the substrate for catalysis. The synthesis of ketoisophorone was demonstrated both as a one-pot two-step process and as a cascade process employing designer cells co-expressing the two biocatalysts, with a productivity of up to 1.4 g L−1 d−1. [ABSTRACT FROM AUTHOR]