Broad Tolerance Research Articles

A Nickel Anchored Covalent Organic Framework as Unimolecular Metallaphotocatalyst for Visible Light Driver C-P Bond Coupling Reaction.

The urgent need to develop a sustainable and environmentally friendly method for synthesizing organophosphine compounds is underscored by their extensive applications in organic synthesis, coordination chemistry, medicinal chemistry, and photoelectric materials. Metalated covalent organic frameworks (MCOFs), which seamlessly integrate the inherent photo properties of COF with the catalytic capabilities of metal ions, offer an optimal material for efficient transformation of organics sustainably. In this study, we introduce a simple COF with nickel anchorages (Bpy-COF-NiCl2 ) as a unimolecular metallaphotocatalytic system for effective C-P bond formation. This heterogeneous photocatalyst exhibits superior catalytic performance, achieving yields of up to 95 %, and demonstrates broad substrate tolerance and functional group reactivity. Notably, the metallaphotocatalytic system has demonstrated the capability to process aryl bromides to produce the desired product, a feat not previously reported. Finally, the production and reusability test at the gram scale attests to its superior practicality for designing future organic cross-coupling reactions.

Boosting Peroxymonosulfate Activation via CoS/MXene Nanocomposite for Rhodamine B Degradation under Simulated Sunlight Irradiation.

Cobalt-based heterogeneous catalysts have been demonstrated as an effective PMS activator for pollutant degradation. However, the limited active sites on their surface lead to an unsatisfactory catalytic efficiency. Immobilizing the catalysts on the support material can be a promising modification strategy to solve this problem. MXene has been considered as an ideal support material due to its unique morphology and physicochemical properties. Therefore, in this work, the CoS-loaded Ti3 C2 MXene (CoS/Ti3 C2 MXene) catalyst for peroxymonosulfate (PMS) activation was successfully synthesized through a solvothermal method. Under the simulated sunlight irradiation, the CoS/Ti3 C2 MXene+PMS system achieved an impressive efficiency in removing the organic pollutant rhodamine B (97.2 % in 10 min). Among the tested catalysts, 30 %-CoS-TC stood out, exhibited a broad pH tolerance from 5 to 9 and maintained robust degradation performance over cycles. Upon detailed analysis, the degradation mechanism revealed the collaborative action dominated by singlet oxygen, and supplemented by photogenerated holes and superoxide radicals in the process. Notably, the sandwich-like structure of MXene played a pivotal role, not only dispersing the CoS particles evenly on the surface of catalysts, but also providing ample space for the active sites, thus accelerating the PMS activation for the degradation of rhodamine B. Overall, this study developed an innovative MXene-based catalyst for the application of environmental remediation.

Metal-Free Oxidative Formation of Aryl Esters by Catalytic Coupling of Acyl and Sulfonyl Chlorides with Arylboronic Acids.

A practical and efficient synthesis of aryl esters was developed through metal-free oxidation. This reaction employs stable and readily available acyl or sulfonyl chlorides and arylboronic acids as the starting materials and proceeds under mild reaction conditions without additional precious metal catalysts. This new strategy exhibits broad substrate tolerance and operational simplicity and gives diverse aryl esters in moderate to high yields.

Photophysiological responses of bottom sea-ice algae to fjord dynamics and rapid freshening

Sea ice algae have a broad salinity tolerance but can experience stress during rapid decreases in salinity that occur with seasonal ice melt and during ice sample melt. This study investigated the impact of salinity on the photophysiological responses of bottom-ice algal communities from two Svalbard fjords (Tempelfjorden and Van Mijenfjorden). To further investigate the impact of salinity alone, and particularly to rapid freshening, the responses of a lab-cultured ice algal community from Van Mijenfjorden were assessed. Photophysiological responses were mainly determined via 14C-based incubations which provided photosynthesis-irradiance curves. Main findings showed that i) the bottom-ice algal community in Tempelfjorden was characterized by lower photosynthetic efficiency and chlorophyll a biomass than the Van Mijenfjorden communities, and ii) a lab-cultured ice algal community from Van Mijenfjorden dominated by pennate diatoms had significantly lower photosynthetic efficiency, maximum photosynthesis and photoacclimation index after a decrease in salinity from 33 to 10. The lower photosynthetic efficiency and chlorophyll a biomass at Tempelfjorden may be attributed to the almost two-fold lower bulk-ice salinity in Tempelfjorden compared to Van Mijenfjorden, which was likely associated with freshwater inputs from the tidewater glacier Tunabreen during sea ice formation. Other factors such as under-ice light intensities, brine volume fraction and brine nutrient concentrations likely also contributed to variability in ice algal response. Furthermore, experimental results indicated that the cultured Van Mijenfjorden community was negatively impacted by a rapid (within 4 to 24 h) reduction in salinity from 33 to 10. We further documented a significant start of recovery of these algae after 168 h. From this work, we surmise that decreases in surface water salinity, for example arising from the intensifying freshening of fjord waters, may only cause temporary changes in ice algal photoacclimation state and thus in chlorophyll a biomass. Further, this study also supports the need for salinity buffered melt of sea ice samples to reduce artificial bias in biological measurements.

Unveiling Enhanced Electrostatic Repulsion in Silica Nanosphere Assembly: Formation Dynamics of Body-Centered-Cubic Colloidal Crystals.

We demonstrate the effective establishment of long-range electrostatic interactions among colloidal silica nanospheres through acid treatment, enabling their assembly into colloidal crystals at remarkably low concentrations. This novel method overcomes the conventional limitation in colloidal silica assembly by removing entrapped NH4+ ions and enhancing the electrical double layer (EDL) thickness, offering a time-efficient alternative to increase electrostatic interactions compared with methods like dialysis. The increased EDL thickness facilitates the assembly of SiO2 nanospheres into a body-centered-cubic lattice structure at low particle concentrations, allowing for broad spectrum tunability and high tolerance to particle size polydispersity. Further, we uncover a disorder-order transition during colloidal crystallization at low particle concentrations, with the optimal concentration for crystal formation governed by both thermodynamic and kinetic factors. This work not only provides insights into assembly mechanisms but also paves the way for the design and functionalization of colloidal silica-based photonic crystals in diverse applications.

De Novo Discovery of Cysteine Frameworks for Developing Multicyclic Peptide Libraries for Ligand Discovery.

Conserved cysteine frameworks are essential components of disulfide-rich peptides (DRPs), which dominantly define the structural diversity of both naturally occurring and de novo-designed DRPs. However, there are only very limited numbers of conserved cysteine frameworks, and general methods enabling de novo discovery of cysteine frameworks with robust foldability are still not available. Here, we devised a "touchstone"-based strategy that relies on chasing oxidative foldability between two individual disulfide-rich folds on the phage surface to discover new cysteine frameworks from random sequences. Unique cysteine frameworks with a high degree of compatibility with phage display systems and broad sequence tolerance were successfully identified, which were subsequently exploited for the development of multicyclic DRP libraries, enabling the rapid discovery of new peptide ligands with low-nanomolar and picomolar binding affinity. This study provides an unprecedented method for exploring and exploiting the sequence and structure space of DRPs that is not readily accessible by existing strategies, holding the potential to revolutionize the study of DRPs and significantly advance the design and discovery of multicyclic peptide ligands and drugs.

Surfactant-Mediated Crystalline Structure Evolution Enabling the Ultrafast Green Synthesis of Bismuth-MOF in Aqueous Condition.

Green synthesis of stable metal-organic frameworks (MOFs) with permanent and highly ordered porosity at room temperature without needing toxic and harmful solvents and long-term high-temperature reactions is crucial for sustainable production. Herein, a rapid and environmentally friendly synthesis strategy is reported to synthesize the complex topological bismuth-based-MOFs (Bi-MOFs),[Bi9(C9H3O6)9(H2O)9] (denoted CAU-17), in water under ambient conditions by surfactant-mediatedsonochemical approach, which could also be applicable to other MOFs. This strategy explores using cetyltrimethylammonium bromide (CTAB) amphiphilic molecules as structure-inducing agents to control the removal of non-coordinated water (dehydration) and enhance the degree of deprotonation of the ligands, thereby regulating the coordination and crystallization in aqueous solutions. In addition, another two new strategies for synthesizing CAU-17 by crystal reconstruction and one-step synthesis in binary solvents are provided, and the solvent-induced synthesis mechanism of CAU-17 is studied. The as-prepared CAU-17 presents a competitive iodine capture capability and effective delivery of the antiarrhythmic drug procainamide (PA) for enteropatia due to the broad pH tolerance and the unique phosphate-responsive destruction in the intestine. The findings will provide valuable ideas for the follow-up study of surfactant-assisted aqueous synthesis of MOFs and their potential applications.

Bicyclopentylation of Alcohols with Thianthrenium Reagents.

Herein we present the first method for the synthesis of bicyclo[1.1.1]pentyl (BCP) alkyl ethers from alcohols. The reaction uses BCP-thianthrenium reagents and is catalyzed by a dual copper/photoredox catalyst system. Unlike known alkylations of tertiary alcohols via carbocation intermediates, our Cu-mediated radical process circumvents the labile BCP carbocations. The approach demonstrates a broad tolerance for functional groups when applied to primary, secondary, and even tertiary alcohols. In addition, we highlight the utility of this method in late-stage functionalizations of both natural products and pharmaceuticals as well as in the rapid construction of BCP analogs of known pharmaceuticals that would otherwise be difficult to access.

Metal–organic framework–derived CeO2 catalyst supported by carboxyl–functionalized MXene for oxidative coupling of benzyl alcohol with aniline

Direct oxidative coupling of alcohols and amines is a highly sought–after method for imine synthesis, and non–precious metal catalysts have been identified as essential components for their efficient production. Here, we report a CeO2 catalyst that is supported by carboxyl–functionalized MXene (CFMX). The catalyst, referred to as CeO2–C@CFMX–T (where T is the pyrolysis temperature), was prepared by high–temperature pyrolysis of a Ce–based metal–organic framework (MOF) and MXene composite (MOF@MXene) in a nitrogen flow environment. The MOF@MXene composite was synthesized by directly assembling Ce–MOF on the outer surface of MXene, which was pre–functionalized with terminal carboxylated aryl diazonium salts. The developed CeO2–C@CFMX–873 exhibited outstanding catalytic behavior in the oxidative coupling of benzyl alcohol and aniline, without the need for any basic additives. The catalyst achieved high benzyl alcohol conversion (98.9 %), desirable imine selectivity (97.7 %), good recyclability (5 cycles), and broad substrate tolerance (22 examples) under mild conditions (353 K, air atmosphere). It was found that the CFMX support improved the dispersion of CeO2 nanoparticles and alleviated the problem of CeO2 aggregation during pyrolysis. The remarkable activity of CeO2–C@CFMX–873 was attributed to reversible Ce3+/Ce4+ redox pairs, abundant oxygen vacancies, and an appropriate number of acid–base sites.

Synthesis of Symmetrical Disulfides by an NIS/PPh3-Mediated Reductive Self-Coupling of Sulfonyl Hydrazides

AbstractThe present study discloses an NIS/PPh3-mediated reductive self-coupling of arylsulfonyl hydrazides to prepare symmetric diaryl disulfides. This methodology has a broad functional-group tolerance and a high scalability. This strategy permits the introduction of sulfonyl hydrazides into the synthesis of symmetrical organic disulfides without the use of a catalyst or base, and symmetrical aromatic disulfides can be prepared in moderate to excellent isolated yields from inexpensive and readily available starting materials.

An abundant future for quagga mussels in deep European lakes

Quagga mussels have expanded their range across the northern hemisphere in recent decades owing to their dispersal abilities, prolific reproduction rates, and broad ecological tolerances. Their remarkable capacity to filter particulates from the water column has had profound effects on inland aquatic ecosystems. In the North American Great Lakes, quagga mussel populations have increased inexorably since the late 1980’s, but it remains unclear whether quagga mussels will follow a similar trajectory in Europe where they have appeared more recently. Here we apply knowledge from a long-term quagga population monitoring effort in the North American lakes to predict future quagga populations in deep European lakes, where quaggas are quickly becoming a conspicuous part of the underwater landscape. We predict that quagga mussel biomass in Lakes Biel, Constance, and Geneva may increase by a factor of 9–20 by 2045. Like in North America, this increase may be characterized by a shift to larger individuals and deeper depths as the population matures. If realized, this rapid expansion of quagga mussels would likely drive the largest aquatic ecosystem change in deep European lakes since the eutrophication period of the mid-20th century.

Deep Learning-Driven Library Design for the De Novo Discovery of Bioactive Thiopeptides.

Broad substrate tolerance of ribosomally synthesized and post-translationally modified peptide (RiPP) biosynthetic enzymes has allowed numerous strategies for RiPP engineering. However, despite relaxed specificities, exact substrate preferences of RiPP enzymes are often difficult to pinpoint. Thus, when designing combinatorial libraries of RiPP precursors, balancing the compound diversity with the substrate fitness can be challenging. Here, we employed a deep learning model to streamline the design of mRNA display libraries. Using an in vitro reconstituted thiopeptide biosynthesis platform, we performed mRNA display-based profiling of substrate fitness for the biosynthetic pathway involving five enzymes to train an accurate deep learning model. We then utilized the model to design optimal mRNA libraries and demonstrated their utility in affinity selections against IRAK4 kinase and the TLR10 cell surface receptor. The selections led to the discovery of potent thiopeptide ligands against both target proteins (KD up to 1.3 nM for the best compound against IRAK4 and 300 nM for TLR10). The IRAK4-targeting compounds also inhibited the kinase at single-digit μM concentrations in vitro, exhibited efficient internalization into HEK293H cells, and suppressed NF-kB-mediated signaling in cells. Altogether, the developed approach streamlines the discovery of pseudonatural RiPPs with de novo designed biological activities and favorable pharmacological properties.

Biodiversity of aquatic Heteroptera in relation to physico-chemical parameters, the Biological Reserve of Sidi Boughaba and the Merja of Fouarat as a case studies (Gharb Plain, Morocco)

Given their great importance in aquatic ecosystems, the literature on aquatic and semi-aquatic Heteroptera is quite extensive worldwide. However, relatively little literature is available on the taxonomy and distribution of aquatic and semi-aquatic Heteroptera in the Gharb Plain, specifically the two wetland areas classified as Ramsar sites, the Biological Reserve of Sidi oughaba and the Merja of Fouarat. Therefore, the present research aims to study the community of aquatic Heteroptera and the physico-chemical variables of these two wetland areas in the Gharb Plain. Additionally, the research aims to document and authenticate the historical review of aquatic and semi-aquatic Heteroptera in these wetlands. The results obtained show the existence of two groups of Heteroptera species. One group consists of species that are found in several environments due to their broad ecological tolerance. This is the case of, Gerris lacustris (Linnaeus, 1758), G. lateralis (Schummel, 1832), Corixa affinis (Leach, 1817), Notonecta glauca rufescens (Poisson, 1933), Anisops sardia (Herrich-Schaeffer, 1849), Plea leachi (McGregor, Kirk, 1899), Naucoris maculatusconspersus (Stål, 1876), Hydrometra stagnorum (Linnaeus,1758) and Mesovelia vittigera (Horváth, 1895). On the contrary, species conditioned by several physicochemical factors of the environment, Stenoic species, such as Sigara lateralis (Leach, 1817), S. stagnalis (Leach, 1817), Naucoris maculatus angustior (Lethierry, 1877), Nepa rubra rubra (Linné, 1758) and Gerris thoracicus (Schummel, 1832).

Terrestrial Trentepohlia sp. (Ulvophyceae) from alpine and coastal collection sites show strong desiccation tolerance and broad light and temperature adaptation.

For the present study, we collected the Ulvophyceae species Trentepohlia aurea from limestone rock near Berchtesgaden, Germany, and the closely related taxa T. umbrina from Tilia cordata tree bark and T. jolithus from concrete wall both in Rostock, Germany. Freshly sampled material stained with Auramine O, DIOC6, and FM 1-43 showed an intact physiological status. Cell walls were depicted with calcofluor white and Carbotrace. When subjected to three repeated and controlled cycles of desiccation over silica gel (~ 10% relative humidity) followed by rehydration, T. aurea recovered about 50% of the initial photosynthetic yield of photosystem II (YII). In contrast, T. umbrina and T. jolithus recovered to 100% of the initial YII. HPLC and GC analysis of compatible solutes found highest proportions of erythritol in T. umbrina and mannitol/arabitol in T. jolithus. The lowest total compatible solute concentrations were detected in T. aurea, while the C/N ratio was highest in this species, indicative of nitrogen limitation. The prominent orange to red coloration of all Trentepohlia was due to extremely high carotenoid to Chl a ratio (15.9 in T. jolithus, 7.8 in T. aurea, and 6.6. in T. umbrina). Photosynthetic oxygen production was positive up to ~ 1500µmol photons m-2s-1 with the highest Pmax and alpha values in T. aurea. All strains showed a broad temperature tolerance with optima for gross photosynthesis between 20 and 35°C. The presented data suggest that all investigated Trentepohlia species are well adapted to their terrestrial lifestyle on exposed to sunlight on a vertical substrate with little water holding capacity. Nevertheless, the three Trentepohlia species differed concerning their desiccation tolerance and compatible solute concentrations. The lower compatible solute contents in T. aurea explain the incomplete recovery of YII after rehydration.

Gene pyramiding for boosted plant growth and broad abiotic stress tolerance.

Abiotic stresses such as salinity, heat and drought seriously impair plant growth and development, causing a significant loss in crop yield and ornamental value. Biotechnology approaches manipulating specific genes prove to be effective strategies in crop trait modification. The Arabidopsis vacuolar pyrophosphatase gene AVP1, the rice SUMO E3 ligase gene OsSIZ1 and the cyanobacterium flavodoxin gene Fld have previously been implicated in regulating plant stress responses and conferring enhanced tolerance to different abiotic stresses when individually overexpressed in various plant species. We have explored the feasibility of combining multiple favourable traits brought by individual genes to acquire superior plant performance. To this end, we have simultaneously introduced AVP1, OsSIZ1 and Fld in creeping bentgrass. Transgenic (TG) plants overexpressing these three genes performed significantly better than wild type controls and the TGs expressing individual genes under both normal and various abiotic stress conditions, exhibited significantly enhanced plant growth and tolerance to drought, salinity and heat stresses as well as nitrogen and phosphate starvation, which were associated with altered physiological and biochemical characteristics and delicately fine-tuned expression of genes involved in plant stress responses. Our results suggest that AVP1, OsSIZ1 and Fld function synergistically to regulate plant development and plant stress response, leading to superior overall performance under both normal and adverse environments. The information obtained provides new insights into gene stacking as an effective approach for plant genetic engineering. A similar strategy can be extended for the use of other beneficial genes in various crop species for trait modifications, enhancing agricultural production.

Pathway to Construct α-Acyloxy Esters by B(C6F5)3-Catalyzed O-H Insertion of Carboxylic Acids with Sulfoxonium Ylides.

We report the first example of B(C6F5)3-catalyzed O-H insertion reaction of sulfoxonium ylides and carboxylic acids, achieving efficient construction of diester moieties under metal-free condition. This protocol is characterized by broad substrate tolerance, particularly for various phenylacetic acids, and good compatibility with water/air condition, which is superior to most other methods.

Nonsterilized Fermentation of Crude Glycerol for Polyhydroxybutyrate Production by Metabolically Engineered Vibrio natriegens.

Polyhydroxybutyrate (PHB) is an attractive biodegradable polymer that can be produced through the microbial fermentation of organic wastes or wastewater. However, its mass production has been restricted by the poor utilization of organic wastes due to the presence of inhibitory substances, slow microbial growth, and high energy input required for feedstock sterilization. Here, Vibrio natriegens, a fast-growing bacterium with a broad substrate spectrum and high tolerance to salt and toxic substances, was genetically engineered to enable efficient PHB production from nonsterilized fermentation of organic wastes. The key genes encoding the PHB biosynthesis pathway of V. natriegens were identified through base editing and overexpressed. The metabolically engineered strain showed 166-fold higher PHB content (34.95 wt %) than the wide type when using glycerol as a substrate. Enhanced PHB production was also achieved when other sugars were used as feedstock. Importantly, it outperformed the engineered Escherichia coli MG1655 in PHB productivity (0.053 g/L/h) and tolerance to toxic substances in crude glycerol, without obvious activity decline under nonsterilized fermentation conditions. Our work demonstrates the great potential of engineered V. natriegens for low-cost PHB bioproduction and lays a foundation for exploiting this strain as a next-generation model chassis microorganism in synthetic biology.

Genome sequencing of 15 acid-tolerant yeasts.

We report draft genome sequences for 15 non-conventional Saccharomycotina yeast strains obtained from public culture repositories. Included in our collection are eight strains of Pichia with broad tolerance to dicarboxylic acids. The genome sequences of these strains will enable comparative genomics of acid-tolerant phenotypes and strain engineering of non-conventional hosts.

An efficient one-pot multicomponent, Amberlite IR120(H) catalyzed microwave-assisted synthesis of 1,2,4,5-tetrasubstituted-1H-imidazoles: Plausible mechanism and antibacterial evaluation

The present study describes an efficient and convenient one-pot multicomponent, microwave-assisted synthesis of polysubstituted-1H-imidazoles in good yields under mild reaction conditions. The procedure uses inexpensive, nontoxic, and reusable Amberlite IR120(H) as a catalyst. The new method exhibits a broad tolerance for diverse structural moieties, thereby demonstrating the robustness and applicability of the synthetic method. Further synthesized polysubstituted-1H-imidazoles exhibited moderate to good activity against bacterial strains under study.

Photocatalytic N‐Alkylation of NH‐Sulfoximines via Anti‐Markovnikov Hydroamination of Alkenes

AbstractSulfoximines, the isoelectronic with sulfones, represent a class of alternative and intriguing motifs in both discovery program and agrochemistry. N‐Alkylation on imines could significantly improve their bioactivities, but the lack of general method has hindered their further uptake by medicinal chemistry and drug development. Herein, we present a mild photocatalytic anti‐Markovnikov hydroamination of alkenes to construct N‐alkylated sulfoximines with broad substrate tolerance on primary, secondary and tertiary alkyl substituents as well as a diverse range of sulfoximines. The mechanistic studies support the photocatalytic pathway, and demonstrate that the alkene radical cation rather than the iminium radical serves as the key intermediate in the transformation.