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Semi-biological photosynthesis combines synthetic photosensitizers with microbial catalysts to produce sustainable fuels and chemicals from CO 2 . However, the inefficient transfer of photoexcited electrons to microbes leads to limited CO 2 utilization, restricting the catalytic performance of such biohybrid assemblies. Here, we introduce a biological engineering solution to address the inherently sluggish electron uptake mechanism of a methanogen, Methanosarcina barkeri (M. barkeri), by coculturing it with an electron transport specialist, Geobacter sulfurreducens KN400 (KN400), an adapted strain rich with multiheme c-type cytochromes (c-Cyts) and electrically conductive protein filaments (e-PFs) made of polymerized c-Cyts with enhanced capacity for extracellular electron transfer (EET). Integration of this M. barkeri-KN400 co-culture with a synthetic photosensitizer, carbon nitride, demonstrates that c-Cyts and e-PFs, emanating from live KN400, transport photoexcited electrons efficiently from the carbon nitride to M. barkeri for methanogenesis with remarkable long-term stability and selectivity. The demonstrated cooperative interaction between two microbes via direct interspecies electron transfer (DIET) and the photosensitizer to assemble a semi-biological photocatalyst introduces an ecosystem engineering strategy in solar chemistry to drive sustainable chemical reactions., (© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Using a protein scaffold covalently functionalised with a thiamine-inspired N-heterocyclic carbene (NHC), we created an artificial Stetterase (ArtiSt) which catalyses a stereoselective, intramolecular Stetter reaction. We demonstrate that ArtiSt functions under ambient conditions with low catalyst loading. Furthermore, activity can be increased >20 fold by altering the protein scaffold.

The current demand in the field of abusive drug research is to have a highly sensitive and rapid method for detecting ketamine and scopolamine, which are frequently used in drug-facilitated sexual assaults administered via beverages and food. We report here the first electrochemical sensors of N-heterocyclic carbene (NHC) coordinated ruthenium organometallic 1-dimensional polymers and their multi-walled carbon nano tube (MWCNT)-based composite for detecting ketamine and scopolamine. The preparation of ruthenium NHC organometallics and the MWCNT composite as sensors offers significant advantages for electrochemical applications, with enhanced sensitivities of 121.979 and 3.273 μA μM -1 cm -2 for ketamine and scopolamine, respectively, and selectivity in sensing applications. The complex-carbon composite sensor has a low limit of detection i.e. , 0.194 and 3.18 nM for ketamine and scopolamine identification, respectively. Alongside, the selectivity of the composite sensor was evaluated in the presence of other blood constituents, and the study evidenced remarkable discernment towards the title drugs. Furthermore, real-time analyses using the composite sensor demonstrated quantitative identification of ketamine and scopolamine. Therefore, this innovation has the potential to provide valuable tools for forensic investigations and address the urgent need for real-time detection of date rape drugs. This contribution demonstrates a robust proof-of-concept that emphasizes the importance of creating non-enzymatic, environmentally friendly, and cost-effective sensors for on-site sensing applications as point-of-care devices.

Over 70 years after the Miller-Urey experiment, synthesizing amino acids from inorganic molecules still faces low selectivity and poor yield. This study uses solution plasma to synthesize amino acids from CH 4 -NH 3 -H 2 , achieving a yield of 341.0 μg L -1 and a serine-to-glycine ratio of 144.5%, the highest reported for clean synthesis.

N-heterocyclic carbenes (NHCs) represent suitable ligands for rapid and efficient drug design, because they offer the advantage of being easily chemically modified and can bind several substituents, including transition metals as, for instance, gold derivatives. Gold-NHC complexes possess various biological activities and were demonstrated good candidates as anticancer drugs. Besides, carbazole derivatives are characterized by various pharmacological properties, such as anticancer, antibacterial, anti-inflammatory, and anti-psychotropic. Amongst the latter, N-thioalkyl carbazoles were proved to inhibit cancer cells damaging the nuclear DNA, through the inhibition of human topoisomerases. Herein, we report the design, synthesis and biological evaluation of nine new hybrid molecules in which NHC-Au(I) complexes and N-alkylthiolated carbazoles are linked together, in order to obtain novel biological multitarget agents. We demonstrated that the lead hybrid complexes possess anticancer, anti-inflammatory and antioxidant properties, with a high potential as useful tools for treating distinct aspects of several diseases, amongst them cancer., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Aiming to create an innovative series of anti-colorectal cancer agents, we designed in this work hybrid triarylmethane compounds. Three hybrid triarylmethanes and their corresponding N-oxide analogues were successfully synthesized using an efficient procedure that involved connecting two triarylmethane molecules, through mono-, bi-, and triethylene glycol fragments. In our pursuit to develop more soluble molecules, we synthesized a hybrid triarylmethane featuring a lysine-based spacer through a convergent strategy involving 7 steps. All hybrid compounds were assessed for their antiproliferative activity on human HT-29 and HCT116 colorectal cancer (CRC) cell lines. Three pyridine N-oxide analogs demonstrated notable antiproliferative potential among the set of tested compounds, with IC 50 values ranging from 18 to 24 μM on both human CRC cell lines analyzed. A cytotoxicity study conducted on murine fibroblasts revealed that these three active compounds were not toxic at the IC 50 values, indicating their suitability for further drug development. A docking study was conducted on two representative compounds, one for each series and protein kinase B (AKT) was identified as a potential target of their in anti-cancer effects. A computational drug-likeness study predicted favourable oral and intestinal absorption efficiency., (© 2024 The Authors. ChemMedChem published by Wiley-VCH GmbH.)

Earth is expected to have acquired a reduced proto-atmosphere enriched in H 2 and CH 4 through the accretion of building blocks that contain metallic Fe and/or the gravitational trapping of surrounding nebula gas. Such an early, wet, reduced atmosphere that covers a proto-ocean would then ultimately evolve toward oxidized chemical compositions through photochemical processes that involve reactions with H 2 O-derived oxidant radicals and the selective escape of hydrogen to space. During this time, atmospheric CH 4 could be photochemically reprocessed to generate not only C-bearing oxides but also organics. However, the branching ratio between organic matter formation and oxidation remains unknown despite its significance on the abiotic chemical evolution of early Earth. Here, we show via numerical analyses that UV absorptions by gaseous hydrocarbons such as C 2 H 2 and C 3 H 4 significantly suppress H 2 O photolysis and subsequent CH 4 oxidation during the photochemical evolution of a wet proto-atmosphere enriched in H 2 and CH 4 . As a result, nearly half of the initial CH 4 converted to heavier organics along with the deposition of prebiotically essential molecules such as HCN and H 2 CO on the surface of a primordial ocean for a geological timescale order of 10-100 Myr. Our results suggest that the accumulation of organics and prebiotically important molecules in the proto-ocean could produce a soup enriched in various organics, which might have eventually led to the emergence of living organisms.

Because of eco-friendliness, biodegradability and ease of modification, cellulose is deemed as alternative to unrenewable petroleum resources. Nonetheless, it is more indispensable to exploit corn cob cellulose produced from agricultural waste residue as supportive materials in green catalysis. In this study, a new magnetically benzimidazole functionalized cellulose/Fe 3 O 4 derived from corn cob cellulose as a stabilizer agent (Fe 3 O 4 @CL-NHC) was prepared, and palladium was immobilized on this stabilizer (Fe 3 O 4 @CL-NHC-Pd). The catalyst was fully characterized by different techniques including TEM, SEM, and XPS analyses, etc. The abundant hydroxyl groups of cellulose provided uniform dispersion and high stability of palladium, while Fe 3 O 4 as a support offered simple magnetic separation. High efficiency (up to 99 %) was demonstrated by this biocatalyst under green conditions in relatively short reaction times towards Suzuki reactions. Due to collaborative interactions of N-heterocyclic carbene and hydroxyl groups with palladium, the synthesized complex prevented metal leaching effectively (<1 %). Moreover, the magnetic property of this catalyst (43.0 emu g -1 ) provides facile recovery of this composite from the reaction mixture with great ease for several times, which overcomes issues of complicated work-up separation. This work offers a promising avenue to enriching the application of biopolymer from agricultural residue in the potential organic transformations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Intelligent-responsive temporary plugging agents (TPAs) have great potential in the field of oil and gas resource extraction due to their self-adaptability to the environment. However, the transport mechanism of oil and gas molecules, such as aqueous methane solution in intelligent-responsive TPA-modified nano-channels and the blocking behavior of TPA, have not been verified yet. In this work, dissipative particle dynamics simulations (DPD) are conducted to investigate the velocity distribution and the force characteristics of aqueous methane solutions under different driving velocities, as well as the blocking effect of TPA to the flow of solution. Simulation results indicate that aqueous methane solution primarily concentrates in the uncovered area of the TPA and diffuses into the TPA-covered area when the nano-channel is closed. The velocity distribution of the flowing solution in the open nano-channel follows a subparabolic pattern. Methane molecules in the closed nano-channel show sharp oscillations in velocity and force profiles, which can be mitigated by increasing the methane concentration. The designed TPA effectively blocks fluid flow but its head and tail are vulnerable to the shear forces from the fluid. This study enhances the understanding of the nanoflows in the wellbores during the extraction of oil and natural gas resources., (© 2024 Wiley‐VCH GmbH.)

Zeolites are a promising support for Pd catalysts in lean methane (CH 4 ) combustion. Herein, three types of zeolites (H-MOR, H-ZSM-5 and H-Y) were selected to estimate their structural effects and deactivation mechanisms in CH 4 combustion. We show that variations in zeolite structure and surface acidity led to distinct changes in Pd states. Pd/H-MOR with external high-dispersing Pd nanoparticles exhibited the best apparent activity, with activation energy (E a ) at 73 kJ/mol, while Pd/H-ZSM-5 displayed the highest turnover frequency (TOF) at 19.6 × 10 -3 sec -1 , presumably owing to its large particles with more step sites providing active sites in one particle for CH 4 activation. Pd/H-Y with dispersed PdO within pore channels and/or Pd 2+ ions on ion-exchange sites yielded the lowest apparent activity and TOF. Furthermore, Pd/H-MOR and Pd/H-ZSM-5 were both stable under a dry condition, but introducing 3 vol.% H 2 O caused the CH 4 conversion rate on Pd/H-MOR drop from 100% to 63% and that on Pd/H-ZSM-5 decreased remarkably from 82% to 36%. The former was shown to originate from zeolite structural dealumination, and the latter principally owed to Pd aggregation and the loss of active PdO., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

New-to-Nature biocatalysis has emerged as a promising tool in organic synthesis thanks to progress in protein engineering. Notably, hemeproteins have been evolved into robust catalysts for carbene and nitrene transfers and related sigmatropic rearrangements. In this work, we report the first example of a [2,3]-sigmatropic Sommelet-Hauser rearrangement initiated by a carbene transfer of the sperm whale myoglobin mutant L29S,H64V,V68F that was previously reported to catalyze the mechanistically similar [2,3]-sigmatropic Doyle-Kirmse rearrangement. This repurposed heme enzyme catalyzes the Sommelet-Hauser rearrangement between ethyl diazoacetate and benzyl thioethers bearing strong electron-withdrawing substituents with good yields and enantiomeric excess. Optimized catalytic conditions in the absence of any reductant led to an increased asymmetric induction with up to 59% enantiomeric excess. This myoglobin mutant is therefore one of the few catalysts for the asymmetric Sommelet-Hauser rearrangement. This work broadens the scope of abiological reactions catalyzed by iron-carbene transferases with a new example of asymmetric sigmatropic rearrangement., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Organoborons have recently received much attention, while a biocatalytic platform for the synthesis of chiral organoborons is limited only to Rma cytochrome c . In this study, we exploited the other heme protein, neuroglobin (Ngb), and engineered a quadruple mutant, A15C/H64G/V68F/F28M Ngb, by redesigning the heme active site using the structural information on A15C Ngb and molecular docking studies. The enzyme was shown to be efficient in catalyzing carbene transfer B-H insertion reactions between pyridine/quinoline boranes and benzyl 2-diazopropanoates and their derivatives (29 examples). The designed cavity in the heme distal site favors the binding of large volume substrates such as those containing a quinoline, naphthyl, or biphenyl group. As further determined by the X-ray crystallography of 6c , the chiral products are in the R -configuration, with up to 98:2 e.r. Furthermore, both the whole cell and cell lysate containing the enzyme are reactive toward the B-H insertion reactions. This study presents a convenient biocatalytic platform that may be generally applicable for the synthesis of functional chiral organoborons.

Intending to homogenize the biological activities of both quinoxaline and imidazole moieties, the proligand, 1-methyl-3-quinoxaline-imidazolium hexaflurophosphate (1.HPF 6 ), and [Ag(1) 2 ][PF 6 ], (2); [Au(1) 2 ][PF 6 ], (3); and [Au(1)Cl 3 ], (4) NHC complexes were synthesized. All the synthesized compounds were characterized by elemental analysis, NMR, and UV-Vis spectroscopy. Finally, single crystal X-ray structures revealed a linear geometry for complex 2 whereas a square planar geometry for complex 4. The formation of complex 3 was confirmed and supported by its MS spectra. The antibacterial activities of all the synthesized complexes were investigated against gram-positive bacteria and gram-negative bacteria. The Au(III)-NHC complex, 4 showed the highest antibacterial activity with extremely low MIC values against both the bacterial strains (0.24 μg mL -1 ). Monitoring of zeta potential supports the higher activity of complex 4 compared to 2 and 3. ROS production by complex 4 has also been measured in vitro in the CT26 cancer cell lines, which is directly responsible for targetting and killing the bacterial pathogens. Cell cytotoxicity assay using 293T cell lines has been performed to investigate the biocompatibility nature of complex 4. Also, an excellent hemocompatibility was assigned to it from its hemolytic studies, which provide valuable insights into the design of novel antibacterial agents., (© 2024 Wiley-VCH GmbH.)

Biogas offers significant benefits as a renewable energy source, contributing to decarbonization, waste management, and economic development. This comprehensive review examines the historical, technological, economic, and global aspects of biomethane production, focusing on the key players such as China, the European Union, and North America, and associated opportunities and challenges as well as future prospects from an Australia perspective. The review begins with an introduction to biogas, detailing its composition, feedstock sources, historical development, and anaerobic digestion (AD) process. Subsequently, it delves into major biomethane production technologies, including physicochemical absorption, high-pressure water scrubbing (HPWS), amine scrubbing (AS), pressure swing adsorption (PSA), membrane permeation/separation (MP), and other technologies including organic solvent scrubbing and cryogenic separation. The study also discusses general guidelines of techno-economic assessments (TEAs) regarding biomethane production, outlining the methodologies, inventory analysis, environmental life cycle assessment (LCA), and estimated production costs. Challenges and opportunities of biogas utilization in Australia are explored, highlighting and referencing global projections, polarization in production approaches, circularity in waste management, and specific considerations for Australia. The review concludes discussing future perspectives for biomethane, emphasizing the importance of technological advancements, policy support, and investment in realizing its full potential for sustainable energy and waste management solutions., (© 2024 The Authors. ChemSusChem published by Wiley-VCH GmbH.)

N-Heterocyclic carbenes (NHC) are well-recognized ligands of choice for preparing robust transition metal species. However, their use for fabrication of biomedically relevant nanoparticles has been limited to the synthesis of non-targeted particles showing increased tolerance to different aqueous coagulants. In this work, the first example of carbene-coated metal nanoparticles suitable for in vivo applications is presented. Directed design of a novel biscarbene NHC ligand allowed to prepare the first magnetite/gold (Fe 3 O 4 @AuNP@NHC) nanostructures and carbene gold (AuNP@NHC) nanoparticles with significant stability in aqueous solutions and enhanced ability to form bioconjugates. Furthermore, these nanoparticles exhibit an extraordinary property for inorganic nanoparticles: they can endure several additive-free air drying/redispersion cycles without deterioration of their colloidal behavior. Bioconjugated AuNP@NHC and multimodal Fe 3 O 4 @AuNP@NHC demonstrated a successful performance in three distinct applications: lateral flow tests, specific cancer cell targeting, and bioimaging. Thus, the results show the notable advantages of the N-heterocyclic carbene coating of inorganic nanoparticles and their utility for complex biomedical applications., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests. The authors declare the following competing financial interest(s): P.M.I., E.L.K., E.N.M., M.P.N., A.A.S. are the authors of a related patent application filed by Sirius University of Science and Technology. M.P.N. and E.N.M. are stakeholders of Abisense LLC that manufactures the LumoTrace FLUO bioimaging system., (Copyright © 2024 Elsevier B.V. All rights reserved.)

An attractive strategy for efficiently forming CS bonds is through the use of diazo compounds SH insertion. However, achieving good enantioselective control in this reaction within a biocatalytic system has proven to be challenging. This study aimed to enhance the activity and enantioselectivity of to enable asymmetric SH insertion. The researchers conducted site-saturation mutagenesis (SSM) on 5 amino acid residues located around the iron carbenoid intermediate within a distance of 5 Å, followed by iterative saturation mutagenesis (ISM) of beneficial mutants. Through this process, the beneficial variant VHb SH (P54R/V98W) was identified through screening with 4-(methylmercapto) phenol as the substrate. This variant exhibited up to 4-fold higher catalytic efficiency and 6-fold higher enantioselectivity compared to the wild-type VHb. Computational studies were also conducted to elucidate the detailed mechanism of this asymmetric SH insertion, explaining how active-site residues accelerate this transformation and provide stereocontrol., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

ConspectusAs the main component of natural gas and renewable biogas, methane is an abundant, affordable fuel. Thus, there is interest in converting these methane reserves into liquid fuels and commodity chemicals, which would contribute toward mitigating climate change, as well as provide potentially sustainable routes to chemical production. Unfortunately, specific activation of methane for conversion into other molecules is a difficult process due to the unreactive nature of methane C-H bonds. The use of methane activating enzymes, such as methyl-coenzyme M reductase (MCR), may offer a solution. MCR catalyzes the methane-forming step of methanogenesis in methanogenic archaea (methanogens), as well as the initial methane oxidation step during the anaerobic oxidation of methane (AOM) in anaerobic methanotrophic archaea (ANME). In this Account, we highlight our contributions toward understanding MCR catalysis and structure, focusing on features that may tune the catalytic activity. Additionally, we discuss some key considerations for biomanufacturing approaches to MCR-based production of useful compounds.MCR is a complex enzyme consisting of a dimer of heterotrimers with several post-translational modifications, as well as the nickel-hydrocorphin prosthetic group, known as coenzyme F 430 . Since MCR is difficult to study in vitro , little information is available regarding which MCRs have ideal catalytic properties. To investigate the role of the MCR active site electronic environment in promoting methane synthesis, we performed electric field calculations based on molecular dynamics simulations with a MCR from Methanosarcina acetivorans and an ANME-1 MCR. Interestingly, the ANME-1 MCR active site better optimizes the electric field with methane formation substrates, indicating that it may have enhanced catalytic efficiency. Our lab has also worked toward understanding the structures and functions of modified F 430 coenzymes, some of which we have discovered in methanogens. We found that methanogens produce modified F 430 s under specific growth conditions, and we hypothesize that these modifications serve to fine-tune the activity of MCR.Due to the complexity of MCR, a methanogen host is likely the best near-term option for biomanufacturing platforms using methane as a C1 feedstock. M. acetivorans has well-established genetic tools and has already been used in pilot methane oxidation studies. To make methane oxidation energetically favorable, extracellular electron acceptors are employed. This electron transfer can be facilitated by carbon-based materials. Interestingly, our analyses of AOM enrichment cultures and pure methanogen cultures revealed the biogenic production of an amorphous carbon material with similar characteristics to activated carbon, thus highlighting the potential use of such materials as conductive elements to enhance extracellular electron transfer.In summary, the possibilities for sustainable MCR-based methane conversions are exciting, but there are still some challenges to tackle toward understanding and utilizing this complex enzyme in efficient methane oxidation biomanufacturing processes. Additionally, further work is necessary to optimize bioengineered MCR-containing host organisms to produce large quantities of desired chemicals.

A series of new gold(I) and silver(I) N-heterocyclic carbenes bearing a 1-thio-β-d-glucose tetraacetate moiety was synthesized and chemically characterized. The compounds' stability and solubility in physiological conditions were investigated employing a multitechnique approach. Interaction studies with biologically relevant proteins, such as superoxide dismutase (SOD) and human serum albumin (HSA), were conducted via UV-vis absorption spectroscopy and high-resolution ESI mass spectrometry. The biological activity of the compounds was evaluated in the A2780 and A2780R (cisplatin-resistant) ovarian cancer cell lines and the HSkMC (human skeletal muscle) healthy cell line. Inhibition studies of the selenoenzyme thioredoxin reductase (TrxR) were also carried out. The results highlighted that the gold complexes are more stable in aqueous environment and capable of interaction with SOD and HSA. Moreover, these carbenes strongly inhibited the TrxR activity. In contrast, the silver ones underwent structural alterations in the aqueous medium and showed greater antiproliferative activity.

Passive methane oxidation biosystems (PMOBs) are developed as an innovative and cost-effective solution to reduce methane (CH 4 ) emissions from municipal solid waste landfills. A PMOB consists of a methane oxidation layer (MOL) and an underlying gas distribution layer (GDL). The length of unrestricted gas migration (LUGM) has been recently proposed as the design criterion for PMOBs where the LUGM is calculated as the horizontal length along the MOL-GDL interface with the volumetric gas content (θ a ) exceeding the threshold volumetric gas content (θ a,occ ). This paper examined water and gas migration within three PMOBs with different MOL-GDL interfaces subject to precipitation and evaporation using verified numerical models. The results show that the use of a single-phase flow model underestimates the LUGM values of the PMOB for heavy precipitation events, and a two-phase flow model should be used to calculate both the LUGM and the total gas mass flow rate into the MOL when designing PMOBs. Both zig-zag and trapezoidal MOL-GDL interfaces can redistribute the gas mass flow rate at the MOL-GDL interface, while the trapezoidal MOL-GDL interface slightly outperforms the zig-zag MOL-GDL interface for enhancing the total gas mass flow rate into the MOL when comparing with the planar MOL-GDL interface. The zig-zag and trapezoidal MOL-GDL interfaces allow gas migration in the upper part of each PMOB segment even when the lower part of each PMOB segment was filled with water, and thus have a potential to minimize hotspot formation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

From previous studies, it is evident that metal-organic gold(I) complexes have antiproliferative activities. The aim of this study is not only to find new anticancer agents but also to overcome existing cytostatic resistance in cancer cells. The synthesis and medicinal evaluation of two cationic 1,3-disubstituted gold(I) bis-tetrazolylidene complexes 1 and 2 are reported. To determine apoptosis-inducing properties of the complexes, DNA fragmentation was measured using propidium iodide staining followed by flow cytometry. Gold(I) complex 1 targets explicitly malignant cells, effectively inhibiting their growth and selectively inducing apoptosis without signs of necrosis. Even in cells resistant to common treatments such as doxorubicin, it overcomes multidrug resistance and sensitizes existing drug-resistant cells to common cytostatic drugs. It is assumed that gold(I) complex 1 involves the mitochondrial pathway in apoptosis and targets members of the BCL-2 family, enhancing its potential as a therapeutic agent in cancer treatment.

Extracellular electron transfer was essential for degrading recalcitrant pollutants by anaerobic digestion (AD). Therefore, existing studies improved AD efficiency by enhancing the electron transfer from microbes-to-pollutants or inter-microbes. This study synthesized a novel Fe, N co-doped biochar (Fe, N-BC), which could enhance both the microbes-to-pollutants and inter-microbes electron transfer in AD. Detailed characterization data indicated that Fe, N-BC has an ordered mesoporous structure, high specific surface area (463.46 m 2 /g), and abundant redox functional groups (Fe 2+ /Fe 3+ , pyrrolic-N), which translate into excellent biocompatibility and electrochemical properties of Fe, N-BC. By adding Fe, N-BC, the stability and efficiency of the medium-temperature AD system in the treatment of methyl orange (MO) wastewater were improved: obtained a high degradation efficiency of MO (96.8 %) and enhanced the methane (CH 4 ) production by 65 % compared to the control group. Meanwhile, Fe, N-BC reduced the accumulation of volatile fatty acids in the AD system, and the activity of anaerobic granular sludge electron transport system and coenzyme F 420 was enhanced. In addition, Fe, N-BC showed positive enrichment of azo dyes decolorization bacteria (Georgenia) and direct interspecies electron transfer (DIET) synergistic partners (Syntrophobacter, Methanosarcina). Overall, the rapid degradation of MO and enhanced CH 4 production in AD systems by Fe, N-BC is associated with enhancing two electronic pathways, i.e., microbes to MO and DIET between syntrophic bacteria and methanogenic archaea. This study introduced an enhanced "two-pathways of electron transfer" theory, realized by Fe, N-BC. These findings provided new insights into the interactions within AD systems and offer strategies for enhancing their performance with recalcitrant pollutants., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The reaction between glycine-type aminonaphthol derivatives substituted with 2- or 1-naphthol and indole or 7-azaindole has been tested. Starting from 2-naphthol as a precursor, the reaction led to the formation of ring-closed products, while in the case of a 1-naphthol-type precursor, the desired biaryl ester was isolated. The synthesis of a bifunctional precursor starting from 5-chloro-8-hydroxyquinoline, morpholine, and ethyl glyoxylate via modified Mannich reaction is reported. The formed Mannich base 10 was subjected to give bioconjugates with indole and 7-azaindole. The effect of the aldehyde component and the amine part of the Mannich base on the synthetic pathway was also investigated. In favor of having a preliminary overview of the structure-activity relationships, the derivatives have been tested on cancer and normal cell lines. In the case of bioconjugate 16 , as the most powerful scaffold in the series bearing indole and a 5-chloro-8-hydroxyquinoline skeleton, a potent toxic activity against the resistant Colo320 colon adenocarcinoma cell line was observed. Furthermore, this derivative was selective towards cancer cell lines showing no toxicity on non-tumor fibroblast cells.

Design of metal cofactor ligands is essential for controlling the reactivity of metalloenzymes. We investigated a carbene transfer reaction catalyzed by myoglobins containing iron porphyrin cofactors with one and two trifluoromethyl groups at peripheral sites (FePorCF 3 and FePor(CF 3 ) 2 , respectively), native heme and iron porphycene (FePc). These four myoglobins show a wide range of Fe(II)/Fe(III) redox potentials in the protein of +147 mV, +87 mV, +42 mV and -198 mV vs. NHE, respectively. Myoglobin reconstituted with FePor(CF 3 ) 2 has a more positive potential, which enhances the reactivity of a carbene intermediate with alkenes, and demonstrates superior cyclopropanation of inert alkenes, such as aliphatic and internal alkenes. In contrast, engineered myoglobin reconstituted with FePc has a more negative redox potential, which accelerates the formation of the intermediate, but has low reactivity for inert alkenes. Mechanistic studies indicate that myoglobin with FePor(CF 3 ) 2 generates an undetectable active intermediate with a radical character. In contrast, this reaction catalyzed by myoglobin with FePc includes a detectable iron-carbene species with electrophilic character. This finding highlights the importance of redox-focused design of the iron porphyrinoid cofactor in hemoproteins to tune the reactivity of the carbene transfer reaction., (© 2024 The Author(s). Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Coalbed methane thermodynamic extraction, as an emerging ECBM recovery method, can effectively improve gas recovery rates. And clarifying methane diffusion and migration law in coal under thermal stimulation is crucial for the selection of its process parameters. Based on laboratory methane adsorption-release experiments, the evolution law of methane diffusion characteristics with temperature and pressure was studied, and the control mechanism of heat-dependent methane diffusion behavior was explored. The results show that both thermal stimulation and high adsorption pressure accelerated the methane diffusion rate in coal. Adsorption pressure had little effect on methane diffusion percentage, but thermal stimulation promoted a significant increase in diffusion percentage and improved the net methane yield. The influence mechanisms of adsorption pressure and thermal stimulation on methane diffusion characteristics are elucidated in relation to the amount and proportion of methane-activated molecules in the diffusion process. The constant diffusion coefficient of methane is heat-dependent, based on which a diffusion model is derived to accurately predict the methane release process in coal. Additionally, temperature has a more important effect on transient diffusion coefficient than pressure. Thermal stimulation leads to a net increase rather than a decrease in diffusion coefficient in the early diffusion stages and can also accelerate the attenuation of diffusion coefficient, with this intensifying effect becoming more pronounced at higher temperatures. The research results can provide some reference for the determination of coal seam gas content and the selection of heat injection process parameters., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Developing adsorbents suitable for industrial applications that can effectively enhance the separation of methane (CH 4 ) from nitrogen (N 2 ) in coalbed gas is crucial to improve energy recovery and mitigate greenhouse gas emissions. In this study, three modification strategies were implemented on Zr-FUM, including ligand regulation, metal replacement, and ligand doping, to synthesize Zr-FDCA, Al-FUM, and Zr-FUM-FA, with the aim of improving the performance of CH 4 /N 2 separation under humid conditions. The results demonstrated that the promotion of robust orbital overlap and strengthened electrovalent bonding on adsorbents can selectively enhance CH 4 adsorption. As a result, Zr-FUM-FA achieved a saturated CH 4 adsorption capacity of 1.37 mmol/g, a CH 4 working window of 307 s, and a CH 4 /N 2 sorbent selection parameter (Ssp) of 47.31, exceeding the performance of most reported adsorbents. Analyses of the pore structure, surface morphology, and functional groups revealed that the presence of an ultramicropore proximity to CH 4 , reduced static resistance, and enhanced electrovalent bond were key factors for CH 4 separation. Grand Canonical Monte Carlo and Density Functional Theory studies indicated that the introduction of -C-H- in FA played a crucial role in enhancing CH 4 adsorption. Optimization of adsorption parameters using the Aspen adsorption package showed that in a dual-adsorbent bed system, the recovery and purity of CH 4 in Zr-FUM-FA reach 99.5% and 97.3%, respectively, providing important theoretical support for the improvement of CH 4 recovery in the pressure swing adsorption process from coalbed gas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Effects of tetrahydrofuran (THF) concentration on the mixed methane hydrate formation, dissociation, and stability were investigated. The experiment was conducted at 286.2 K and 6 MPa in a quiescent reactor. The presence of THF below 2.5 mol% did not show the evidence of hydrate formation. However, the concentration above 2.5 mol% enhanced the methane formation rate and the methane consumption. Increasing the THF concentration decreased the induction time as the result of the decrease in the surface tension. Moreover, the methane uptake and formation rate increased with the THF concentration due to the higher degree of hydrate nucleation. The methane recovery after the dissociation experiment showed up to 96%. Furthermore, the hydrate stability increased, and the hydrate dissociation kinetics decreased with the increase in the THF concentration. The optimum THF concentration to enhance and improve the hydrate formation kinetics and stability is its stoichiometric concentration.

Metal complexes based on N-heterocyclic carbene (NHC) ligands have emerged as promising broad-spectrum antitumor agents in bioorganometallic medicinal chemistry. In recent decades, studies on cytotoxic metal-NHC complexes have yielded numerous compounds exhibiting superior cytotoxicity compared to cisplatin. Although the molecular mechanisms of these anticancer complexes are not fully understood, some potential targets and modes of action have been identified. However, a comprehensive review of their biological mechanisms is currently absent. In general, apoptosis caused by metal-NHCs is common in tumor cells. They can cause a series of changes after entering cells, such as mitochondrial membrane potential (MMP) variation, reactive oxygen species (ROS) generation, cytochrome c (cyt c) release, endoplasmic reticulum (ER) stress, lysosome damage, and caspase activation, ultimately leading to apoptosis. Therefore, a detailed understanding of the influence of metal-NHCs on cancer cell apoptosis is crucial. In this review, we provide a comprehensive summary of recent advances in metal-NHC complexes that trigger apoptotic cell death via different apoptosis-related targets or signaling pathways, including B-cell lymphoma 2 (Bcl-2 family), p53, cyt c, ER stress, lysosome damage, thioredoxin reductase (TrxR) inhibition, and so forth. We also discuss the challenges, limitations, and future directions of metal-NHC complexes to elucidate their emerging application in medicinal chemistry., (© 2024 Wiley Periodicals LLC.)

Anaerobic methane oxidation (AOM) can drive soil arsenate reduction, a process known as methane-dependent arsenate reduction (M-AsR), which is a critical driver of arsenic (As) release in soil. Low molecular weight organic acids (LMWOAs), an important component of rice root exudates, have an unclear influence and mechanism on the M-AsR process. To narrow this knowledge gap, three typical LMWOAs-citric acid, oxalic acid, and acetic acid-were selected and added to As-contaminated paddy soils, followed by the injection of 13 CH 4 and incubation under anaerobic conditions. The results showed that LMWOAs inhibited the M-AsR process and reduced the As(III) concentration in soil porewater by 35.1-65.7 % after 14 days of incubation. Among the LMWOAs, acetic acid exhibited the strongest inhibition, followed by oxalic and citric acid. Moreover, LMWOAs significantly altered the concentrations of ferrous iron and dissolved organic carbon in the soil porewater, consequently impacting the release of As in the soil. The results of qPCR and sequencing analysis indicated that LMWOAs inhibited the M-AsR process by simultaneously suppressing microbes associated with ANME-2d and arrA. Our findings provide a theoretical basis for modulating the M-AsR process and enhance our understanding of the biogeochemical cycling of As in paddy soils under rhizosphere conditions., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Developing cost-effective and high-performance catalyst systems for dry reforming of methane (DRM) is crucial for producing hydrogen (H 2 ) sustainably. Herein, we investigate using iron (Fe) as a promoter and major alumina support in Ni-based catalysts to improve their DRM performance. The addition of iron as a promotor was found to add reducible iron species along with reducible NiO species, enhance the basicity and induce the deposition of oxidizable carbon. By incorporating 1 wt.% Fe into a 5Ni/10ZrAl catalyst, a higher CO 2 interaction and formation of reducible "NiO-species having strong interaction with support" was observed, which led to an ∼80% H 2 yield in 420 min of Time on Stream (TOS). Further increasing the Fe content to 2wt% led to the formation of additional reducible iron oxide species and a noticeable rise in H 2 yield up to 84%. Despite the severe weight loss on Fe-promoted catalysts, high H 2 yield was maintained due to the proper balance between the rate of CH 4 decomposition and the rate of carbon deposit diffusion. Finally, incorporating 3 wt.% Fe into the 5Ni/10ZrAl catalyst resulted in the highest CO 2 interaction, wide presence of reducible NiO-species, minimum graphitic deposit and an 87% H 2 yield. Our findings suggest that iron-promoted zirconia-alumina-supported Ni catalysts can be a cheap and excellent catalytic system for H 2 production via DRM., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Quantitation of sulfur (S) is vitally important for analysis of agricultural soil and plant samples due to the requirement of S in living organisms. Although inductively coupled plasma mass spectrometry (ICP-MS) is a commonly used and robust instrument for multi-elemental detection, S is usually analysed by ICP-optical emission spectroscopy (OES) since S quantitation poses a particular challenge for ICP-MS due to interferences on all S isotopes. The requirement for analysis by two instruments increases time and cost for sample analysis, hence analysis by one instrument is desirable. The use of reaction gases in ICP-MS can improve the performance by shifting S to a mass for detection where no interference is present. This work explored the potential of methane as a reaction gas for analysis of S in soil and plant samples to give users an alternative option to oxygen. The product ion clusters CH 2 SH + were monitored (m/z 47 and 49 on ICP-MS and with mass shift of +15 from Q1 → Q2 using 32 → 47 and 34 → 49 on triple quadrupole ICP-MS). As expected, triple quadrupole ICP-MS performed better than single quadrupole ICP-MS containing a reaction cell due to the ability to preselect the m/z of choice and remove ions that may react with methane in the reaction cell. The method detection limit (MDL) was 150 mg kg -1 S for plants and 53 mg kg -1 S for soils which is fit for requirements. This is the first-time methane has been reported as a reaction gas for analysis of S and shows promising results for agricultural samples when using a triple quadrupole ICP-MS. Results compared well to those obtained via the more commonly used ICP-optical emission spectroscopy (OES) method with results <20 % for all samples. Interlaboratory comparison samples were within 2 Z-scores of the consensus mean. In the absence of ICP-MS/MS, Q-ICP-MS with detection of cluster m/z 47 was deemed to be suitable for detection of S in plant samples, with acceptable MDL (250 mg kg -1  S), acceptable precision (<20 % RSD) and <20 % variation to the reported ICP-OES result., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Carbene transfer reactions have emerged as pivotal methodologies for the synthesis of complex molecular architectures. Heme protein-catalyzed carbene transfer reactions have shown promising results on model compounds. However, their limited substrate scope has hindered their application in natural product functionalization. Building upon the foundation of previously published work on a carbene transferase-myoglobin variant, this study employs computer-aided protein engineering to design myoglobin variants, using either docking or the deep learning-based LigandMPNN method. These variants were utilized as catalysts in carbene transfer reactions with a selection of monoterpene substrates featuring C-C double bonds, leading to seven target products. This cost-effective methodology broadens the substrate scope for heme protein-catalyzed reactions, thereby opening novel pathways for research in heme protein functionalities and offering fresh perspectives in the synthesis of bioactive molecules., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Carbon capture and utilization (CCU) covers an array of technologies for valorizing carbon dioxide (CO 2 ). To date, most mature CCU technology conducted with capture agents operates against the CO 2 gradient to desorb CO 2 from capture agents, exhibiting high energy penalties and thermal degradation due to the requirement for thermal swings. This Perspective presents a concept of Bio-Integrated Carbon Capture and Utilization (BICCU), which utilizes methanogens for integrated release and conversion of CO 2 captured with capture agents. BICCU hereby substitutes the energy-intensive desorption with microbial conversion of captured CO 2 by the methanogenic CO 2 -reduction pathway, utilizing green hydrogen to generate non-fossil methane., (© 2024. The Author(s).)

Over 20 years ago, the pyrrolysine encoding translation system was discovered in specific archaea. Our Review provides an overview of how the once obscure pyrrolysyl-tRNA synthetase (PylRS) tRNA pair, originally responsible for accurately translating enzymes crucial in methanogenic metabolic pathways, laid the foundation for the burgeoning field of genetic code expansion. Our primary focus is the discussion of how to successfully engineer the PylRS to recognize new substrates and exhibit higher in vivo activity. We have compiled a comprehensive list of ncAAs incorporable with the PylRS system. Additionally, we also summarize recent successful applications of the PylRS system in creating innovative therapeutic solutions, such as new antibody-drug conjugates, advancements in vaccine modalities, and the potential production of new antimicrobials.

A new eco-friendly method for the synthesis of mono- and multifunctional organosulfur compounds, based on the process between ynals and thiols, catalyzed by bulky N -heterocyclic carbene (NHC), was designed and optimized. The proposed organocatalytic approach allows the straightforward formation of a broad range of thioesters and sulfenyl-substituted aldehydes in yields above 86%, in mild and metal-free conditions. In this study, thirty-six sulfur-based derivatives were obtained and characterized by spectroscopic methods.

In this study, we synthesized novel Pd(II)-indenyl complexes using various N -heterocyclic carbene (NHC) ligands, including chelating NHC-picolyl, NHC-thioether, and diNHC ligands, and two monodentate NHCs. Transmetalation reactions between a Pd(II)-indenyl precursor and silver-NHC complexes were generally employed, except for chelating diNHC derivatives, which required direct reaction with bisimidazolium salts and potassium carbonate. Characterization included NMR, HRMS analysis, and single-crystal X-ray diffraction. In vitro on five ovarian cancer cell lines showed notable cytotoxicity, with IC 50 values in the micro- and submicromolar range. Some compounds exhibited intriguing selectivity for cancer cells due to higher tumor cell uptake. Mechanistic studies revealed that monodentate NHCs induced mitochondrial damage while chelating ligands caused DNA damage. One chelating NHC-picolyl ligand showed promising cytotoxicity and selectivity in high-grade serous ovarian cancer models, supporting its consideration for preclinical study.

ConspectusLife is an exergonic chemical reaction. The same was true when the very first cells emerged at life's origin. In order to live, all cells need a source of carbon, energy, and electrons to drive their overall reaction network (metabolism). In most cells, these are separate pathways. There is only one biochemical pathway that serves all three needs simultaneously: the acetyl-CoA pathway of CO 2 fixation. In the acetyl-CoA pathway, electrons from H 2 reduce CO 2 to pyruvate for carbon supply, while methane or acetate synthesis are coupled to energy conservation as ATP. This simplicity and thermodynamic favorability prompted Georg Fuchs and Erhard Stupperich to propose in 1985 that the acetyl-CoA pathway might mark the origin of metabolism, at the same time that Steve Ragsdale and Harland Wood were uncovering catalytic roles for Fe, Co, and Ni in the enzymes of the pathway. Subsequent work has provided strong support for those proposals.In the presence of Fe, Co, and Ni in their native metallic state as catalysts, aqueous H 2 and CO 2 react specifically to formate, acetate, methane, and pyruvate overnight at 100 °C. These metals (and their alloys) thus replace the function of over 120 enzymes required for the conversion of H 2 and CO 2 to pyruvate via the pathway and its cofactors, an unprecedented set of findings in the study of biochemical evolution. The reactions require alkaline conditions, which promote hydrogen oxidation by proton removal and are naturally generated in serpentinizing (H 2 -producing) hydrothermal vents. Serpentinizing hydrothermal vents furthermore produce natural deposits of native Fe, Co, Ni, and their alloys. These are precisely the metals that reduce CO 2 with H 2 in the laboratory; they are also the metals found at the active sites of enzymes in the acetyl-CoA pathway. Iron, cobalt and nickel are relicts of the environments in which metabolism arose, environments that still harbor ancient methane- and acetate-producing autotrophs today. This convergence indicates bedrock-level antiquity for the acetyl-CoA pathway. In acetogens and methanogens growing on H 2 as reductant, the acetyl-CoA pathway requires flavin-based electron bifurcation as a source of reduced ferredoxin (a 4Fe4S cluster-containing protein) in order to function. Recent findings show that H 2 can reduce the 4Fe4S clusters of ferredoxin in the presence of native iron, uncovering an evolutionary precursor of flavin-based electron bifurcation and suggesting an origin of FeS-dependent electron transfer in proteins. Traditionally discussed as catalysts in early evolution, the most common function of FeS clusters in metabolism is one-electron transfer, also in radical SAM enzymes, a large and ancient enzyme family. The cofactors and active sites in enzymes of the acetyl-CoA pathway uncover chemical antiquity in metabolism involving metals, methyl groups, methyl transfer reactions, cobamides, pterins, GTP, S -adenosylmethionine, radical SAM enzymes, and carbon-metal bonds. The reaction sequence from H 2 and CO 2 to pyruvate on naturally deposited native metals is maximally simple. It requires neither nitrogen, sulfur, phosphorus, RNA, ion gradients, nor light. Solid-state metal catalysts tether the origin of metabolism to a H 2 -producing, serpentinizing hydrothermal vent.

The hydrogenation of CO 2 to CH 4 has gained considerable interest in terms of sustainable energy and environmental mitigation. In this regard, the present work aims to investigate the adsorptive concentration and CO 2 methanation performance over CoFe and NiFe bimetallic catalysts supported on fumed alumina-silica SA96 support at 170-450 °C and under atmospheric pressure. The catalysts were prepared by wet impregnation method, subjected to calcination and further reduced with hydrogen, and their performance in CO 2 methanation was investigated in a hydrogen-rich 2%CO 2 -55%H 2 -43%He gas mixture. In this study, we describe the crystal and mesoporous structures of the prepared catalysts by in-situ XRD and ex-situ nitrogen adsorption, evaluate the NiFe and CoFe metal surface states before and after catalysis by XPS, visualize the surface morphology by SEM, estimate the catalytic activity by gas chromatography, and investigate the adsorbed surface species, showing the presence of *HCOO/*HCO and *CO intermediates, determine two possible pathways of CH 4 formation on the studied catalysts by temperature-programmed desorption mass spectrometry, and correlate the structural and surface properties with high CO 2 conversions up to 100% and methanation selectivities up to 72%. The latter is related to changes in the elemental chemical states and surface composition of CoFe and NiFe nanocatalysts induced by treatment under reaction conditions, and the surface reconstruction during catalysis transfers the part of active 3d transition metals into the pores of the SA96 support. Our thorough characterization study with complementary techniques allowed us to conclude that this high activity is related to the formation of catalytically active Ni/Ni 3 Fe and Co/CoFeO x nanoscale crystallites under H 2 reduction and their maintenance under CO 2 methanation conditions. The successfully applied combination of CO 2 chemisorption and thermodesorption techniques demonstrates the ability to adsorb the CO 2 molecules by supported NiFe and CoFe nanocatalysts and the pure alumina-silica SA96 support., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Poly(butylene adipate-co-terephthalate) (PBAT) is a biodegradable plastic that is difficult to degrade under both mesophilic and thermophilic anaerobic conditions. In this study, the impact of the thermo-alkaline pretreatment (48 h, 70 °C, 1 % w/v NaOH) on the anaerobic degradation (AD) of PBAT, poly(lactic acid) (PLA) and PBAT/PLA blended plastics was investigated. Under mesophilic conditions, pretreatment only improved the methane yield of PBAT/PLA/starch plastic (100 days, 51 and 34 NmL/g VS add for the treated and original plastics, respectively). Under thermophilic conditions, the pretreatment increased the methanogenic rate of PLA, PBAT and PBAT/PLA/starch plastic at the beginning stage (22 days, 35 and 79 NmL/g VS add for original and treated PBAT, respectively), but did not change the methane yield at the end of the incubation (100 days, 91 NmL/g VS add for original and treated PBAT). The reduction in the molecular weight and the formation of pore structures on the plastic surface accelerated the utilization of plastics by microorganisms. Furthermore, the pretreated plastics tend to form microplastics (MPs) with size predominantly below 500 µm (>90 %). The numbers of MPs dynamically changed with the degradation time. Several genera of bacteria showed specific degradation of biodegradable plastics under thermophilic conditions, including Desulfitibacter, Coprothermobacter, Tepidimicrobium, c&#95; D8A-2 and Thermacetogenium. The results suggest that more attention should be paid to the problem of MPs arising from the thermo-alkaline pretreatment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Tris(pyrazolyl)methane (tpm), 2,2,2-tris(pyrazolyl)ethanol (tpmOH) and its esterification derivatives with ibuprofen and flurbiprofen (tpmIBU and tpmFLU) were used as ligands to obtain complexes of the type [Fe(tpm X ) 2 ]Cl 2 (1-4). The tpmIBU and tpmFLU ligands and corresponding complexes 3 and 4 were characterized by IR and multinuclear NMR spectroscopy, and the structure of tpmIBU was elucidated by single crystal X-ray diffraction. Complexes 1-4 were also assessed for their behaviour in aqueous media (solubility in D 2 O, octanol/water partition coefficient, stability in physiological-like conditions). The antiproliferative activity of ligands and complexes was determined on A2780, A2780cis and A549 cancer cell lines and the non-cancerous HEK 293T and BJ cell lines. The ligands and complexes were investigated for their ability to inhibit COX-2 (cyclooxygenase) and HNE (4-hydroxynonenal) enzymes. Complexes 3 and 4 exhibited cytotoxicity that may be attributed predominantly to their bioactive fragments, while DNA binding and enhancement of ROS production do not appear to play any significant role.

In this study, peptides designed using fragments of an antifreeze protein (AFP) from the freeze-tolerant insect Tenebrio molitor, TmAFP, were evaluated as inhibitors of clathrate hydrate formation. It was found that these peptides exhibit inhibitory effects by both direct and indirect mechanisms. The direct mechanism involves the displacement of methane molecules by hydrophobic methyl groups from threonine residues, preventing their diffusion to the hydrate surface. The indirect mechanism is characterized by the formation of cylindrical gas bubbles, the morphology of which reduces the pressure difference at the bubble interface, thereby slowing methane transport. The transfer of methane to the hydrate interface is primarily dominated by gas bubbles in the presence of antifreeze peptides. Spherical bubbles facilitate methane migration and potentially accelerate hydrate formation; conversely, the promotion of a cylindrical bubble morphology by two of the designed systems was found to mitigate this effect, leading to slower methane transport and reduced hydrate growth. These findings provide valuable guidance for the design of effective peptide-based inhibitors of natural-gas hydrate formation with potential applications in the energy and environmental sectors., (© 2024 Author(s). Published under an exclusive license by AIP Publishing.)

In the current global context, there is a pressing need to curtail greenhouse gas emissions, making the utilization of a coal and zero-carbon energy blend an imperative strategy for reducing carbon emissions from coal-fired power generation. The planar flame burner serves as a tool to simulate the temperature and atmospheric conditions within the reburning zone, facilitating extensive examination of the physical and chemical structural alterations, as well as the nitrogen oxide reduction potential, during NH 3 /CH 4 activation for reburning pulverized coal. Experimental results underscore that blending high-activity fuels optimizes the combustion performance of coal char. Through the addition of NH 3 and CH 4 , the NO reduction capability of coal char is bolstered by approximately 0.67 times compared to sole reliance on recirculating flue gas transport. Furthermore, NH 3 introduction facilitates the conversion of C]O double bonds into C-O single bonds, rendering them more amenable to reduction by NO. While the joint influence of NH 3 and CH 4 does not significantly impact char particle size, it does foster the evolution of N-Q to N-5 and N-6 on the char surface. Furthermore, there was a significant increase in the BET-specific surface area, which rose by 50%. Additionally, the total pore volume increased by approximately 21.43%. The comprehensive understanding of NH 3 and CH 4 modified pulverized coal reburning technology holds significant promise for optimizing power plant operations and mitigating carbon dioxide and nitrogen oxide emissions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

The CH 4 storage by adsorption on activated carbons for natural gas handling has gained interest due to the appearance of lightweight materials with large surface areas and pore volumes. Consequently, kinetic parameters estimation of the adsorptive process can play a crucial role in understanding and scaling up the system. Concerning its versatility, banana peel (BP) is a biomass with potential for obtaining different products, such as biochar, a solid residue from the biomass' thermal decomposition of difficult disposal, where through an activation process, the material porous features are taken advantage to application as adsorbent of gaseous substances. This research reported data for the CH 4 adsorption kinetic modeling by biochar from BP pyrolysis. The activated biochar textural characterization showed particles with fine mesoporous structure (pore diameter ranging between 29.39 and 55.62 Å). Adsorption kinetic analysis indicated that a modified pseudo-first-order model was the most suitable to represent the experimental data, with equilibrium adsorption of 28 mg g -1 for the samples activated with 20.0% vol wt. -1 of H 3 PO 4 and pyrolysis at 500 °C. The equilibrium constant was consistent with the Freundlich isotherm model, suggesting a physisorption mechanism, and led to a non-ideal, reversible, and not limited to monolayer CH 4 adsorption., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Lignocellulose is an abundant renewable bio-macromolecular complex, which can be used to produce biomethane and other high-value products. The lignin, presents in lignocellulose is typically regarded as an inhibitor of anaerobic digestion. Therefore, it is crucial to develop a novel selective separation strategy to achieve efficient biomethane production and all-component utilization of biomass. Hence, a combination of two-step pretreatment and solid-state anaerobic digestion was employed to enhance the production of biomethane and to generate valuable chemicals from poplar waste. Optimal conditions (4 % acetic acid, 170 °C, and 40 min) resulted in 70.85 % xylan removal, yielding 50.28 % xylo-oligosaccharides. The effect of a strong acid 4-CSA-based novel three-constituent DES on delignification was investigated from 80 °C to 100 °C; the cellulose content of DES pretreated poplar increased from 64.11 % to 80.92 %, and the delignification rate increased from 49.0 % to 90.4 %. However, high delignification of the pretreated poplar (DES-100 and DES-110) led to a rapid accumulation of volatile organic acids during the hydrolysis and acidogenesis stages, resulting in methanogenesis inhibition. The highest biomethane yield of 208 L/kg VS was achieved with DES-80 (49.0 % delignification), representing a 148 % improvement compared over untreated poplar. This approach demonstrates the potential for comprehensive utilization of all components of biomass waste., Competing Interests: Declaration of competing interest The authors declare that they have no any competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Antimicrobial resistance (AMR) has been emerging as a major global health threat and calls for the development of novel drug candidates. Metal complexes have been demonstrating high efficiency as antibacterial agents that differ substantially from the established types of antibiotics in their chemical structures and their mechanism of action. One strategy to exploit this potential is the design of metal-based hybrid organometallics that consist of an established antibiotic and a metal-based warhead that contributes an additional mechanism of action different from that of the parent antibiotic. In this communication, we describe the organometallic hybrid antibiotic 2c, in which the drug metronidazole is connected to a gold(I) N-heterocyclic carbene warhead that inhibits bacterial thioredoxin reductase (TrxR). Metronidazole can be used for the treatment with the obligatory anaerobic pathogen Clostridioides difficile (C. difficile), however, resistance to the drug hampers its clinical success. The gold organometallic conjugate 2c was an efficient inhibitor of TrxR and it was inactive or showed only minor effects against eucaryotic cells and bacteria grown under aerobic conditions. In contrast, a strong antibacterial effect was observed against both metronidazole-sensitive and -resistant strains of C. difficile. This report presents a proof-of-concept that the design of metal-based hybrid antibiotics can be a viable approach to efficiently tackle AMR., (© 2024. The Author(s).)

Methane, either as natural gas or as a resource obtained from various bioprocesses (e.g., digestion, landfill) can be converted to carbon and hydrogen according to. CH 4 (g)→C(s)+2H 2 (g)ΔH 298K =74.8kJ/mol. Previous research has stressed the growing importance of substituting the high-temperature Steam Methane Reforming (SMR) by a moderate temperature Catalytic Methane Decomposition (CMD). The carbon formed is moreover of nanotube nature, in high industrial demand. To avoid the use of an inert support for the active catalyst species, e.g., Al 2 O 3 for Fe, leading to a progressive contamination of the catalyst by support debris and coking of the catalyst, the present research investigates the use of carbon nanotubes (CNTs) as Fe-support. Average CH 4 conversions of 75-85% are obtained at 700 °C for a continuous operation of 40 h. The produced CNT from the methane conversion can be continuously removed from the catalyst bed by carry-over due to its bulk density difference (∼120 kg/m 3 ) with the catalyst itself (∼1500 kg/m 3 ). CNT properties are fully specified. No thermal regeneration of the catalyst is required. A tentative process layout and economic analysis demonstrate the scalability of the process and the very competitive production costs of H 2 and CNT., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Methyl-coenzyme M reductase (MCR) is a multi-subunit (α 2 β 2 γ 2 ) enzyme responsible for methane formation via its unique F 430 cofactor. The genes responsible for producing MCR (mcrA, mcrB and mcrG) are typically colocated with two other highly conserved genes mcrC and mcrD. We present here the high-resolution crystal structure for McrD from a human gut methanogen Methanomassiliicoccus luminyensis strain B10. The structure reveals that McrD comprises a ferredoxin-like domain assembled into an α + β barrel-like dimer with conformational flexibility exhibited by a functional loop. The description of the M. luminyensis McrD crystal structure contributes to our understanding of this key conserved methanogen protein typically responsible for promoting MCR activity and the production of methane, a greenhouse gas., (© 2024 The Author(s). FEBS Open Bio published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

Xanthines are purine derivatives predominantly found in plants. These include compounds such as caffeine, theophylline, and theobromine and exhibit a variety of pharmacological properties, demonstrating efficacy in treating neurodegenerative disorders, respiratory dysfunctions, and also cancer. The versatile attributes of these materials render them privileged scaffolds for the development of compounds for various biological applications. Xanthines are N-heterocyclic carbene precursors that combine a pyrimidine and an imidazole ring. Owing to their biological relevance, xanthines have been employed as N-heterocyclic carbenes in the development of metallodrugs for anticancer and antimicrobial purposes. In this conceptual review, we examine key examples of N-heterocyclic carbene complexes derived from caffeine and other xanthines, elucidating their synthetic methods and describing their pertinent medicinal applications., (© 2024 The Authors. ChemMedChem published by Wiley-VCH GmbH.)

Anaerobic digestion for flexible biogas production can lead to digestion inhibition under high shock loads. While steel slag addition has shown promise in enhancing system buffering, its limitations necessitate innovation. This study synthesized the nitrogen-doped activated carbon composite from steel slag to mitigate intermediate product accumulation during flexible biogas production. Material characterization preceded experiments introducing the composite into anaerobic digestion systems, evaluating its impact on methane production efficiency under hydraulic and concentration sudden shocks. Mechanistic insights were derived from microbial community and metagenomic analyses, facilitating the construction of the modified Anaerobic Digestion Model No. 1 (ADM1) to quantitatively assess the material's effects. Results indicate superior resistance to concentration shocks with substantial increment of methane production rate up to 33.45% compared with control group, which is mediated by direct interspecies electron transfer, though diminishing with increasing shock intensity. This study contributes theoretical foundations for stable flexible biogas production and offers an effective predictive tool for conductor material reinforcement processes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Encephalitozoon intestinalis is an opportunistic microsporidian parasite that primarily infects immunocompromised individuals, such as those with HIV/AIDS or undergoing organ transplantation. Leishmaniasis is responsible for parasitic infections, particularly in developing countries. The disease has not been effectively controlled due to the lack of an effective vaccine and affordable treatment options. Current treatment options for E. intestinalis infection and leishmaniasis are limited and often associated with adverse side effects. There is no previous study in the literature on the antimicrosporidial activities of Ag(I)-N-heterocyclic carbene compounds. In this study, the in vitro antimicrosporidial activities of previously synthesized Ag(I)-N-heterocyclic carbene complexes were evaluated using E. intestinalis spores cultured in human renal epithelial cell lines (HEK-293). Inhibition of microsporidian replication was determined by spore counting. In addition, the effects of the compounds on Leishmania major promastigotes were assessed by measuring metabolic activity or cell viability using a tetrazolium reaction. Statistical analysis was performed to determine significant differences between treated and control groups. Our results showed that the growth of E. intestinalis and L. major promastigotes was inhibited by the tested compounds in a concentration-dependent manner. A significant decrease in parasite viability was observed at the highest concentrations. These results suggest that the compounds have potential anti-microsporidial and anti-leishmanial activity. Further research is required to elucidate the underlying mechanisms of action and to evaluate the efficacy of the compounds in animal models or clinical trials., (© 2024. The Author(s).)

The processes leading to high levels of arsenic (As), iron (Fe), and manganese (Mn) in groundwater, in a naturally reducing aquifer at a controlled municipal landfill site, are investigated. The challenge is to distinguish the natural water-rock interaction processes, that allow these substances to dissolve in groundwater, from direct pollution or enhanced dissolution of hydroxides as undesired consequences of the anthropic activities above. Ordinary groundwater monitoring of physical-chemical parameters and inorganic compounds (major and trace elements) was complemented by environmental isotopes of groundwater (tritium, deuterium, oxygen-18 and carbon-13) and dissolved gases (carbon-13 of methane and carbon dioxide and carbon-14 of methane). Pearson/Spearman correlation indices, as well as Principal Component Analysis (PCA), were used to determine the main correlations among variables. The concurrent presence of As, Fe and CH 4 , as reported in similar anoxic environments, suggests that anaerobic oxidation of methane could drive the reductive dissolution of As-rich Fe(III)(hydro)oxides. Manganese is more sensitive to carbon dioxide, possibly due to a decrease in pH which accelerates the dissolution of Mn-oxides. Finally, we found that tritium and deuterium, which have been used for decades as leachate tracer in groundwater, may be subject to false positives due to the reuse of water recovered from leachate treatment (which has the same isotopic signature of leachate) within the plants, to comply with the requirements of the circular economy. The integration of the environmental isotope analysis into the traditional monitoring approach can effectively support the comprehension of processes. However, this strategy needs to be complemented by a good conceptual hydrogeological model and expert evaluation to avoid misinterpretations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)