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Fixation and demineralization protocols for bone marrow (BM) across diagnostic laboratories are not standardized. How different protocols affect histomorphology and DNA amplification is incompletely understood. In this study, 2 fixatives and 3 demineralization methods were tested on canine BM samples. Twenty replicate sternal samples obtained within 24 hours of death were fixed overnight in either acetic acid-zinc-formalin (AZF) or 10% neutral-buffered formalin (NBF) and demineralized with formic acid for 12 hours. Another 53 samples were fixed in AZF and demineralized with hydrochloric acid for 1-hour, formic acid for 12 hours, or ethylenediamine tetraacetic acid (EDTA) for 24 hours. Histologic sections were scored by 4 raters as of insufficient, marginal, good, or excellent quality. In addition, DNA samples extracted from sections treated with the different fixation and demineralization methods were amplified with 3 sets of primers to conserved regions of T cell receptor gamma and immunoglobulin heavy chain genes. Amplification efficiency was graded based on review of capillary electrophoretograms. There was no significant difference in the histomorphology scores of sections fixed in AZF or NBF. However, EDTA-based demineralization yielded higher histomorphology scores than demineralization with hydrochloric or formic acid, whereas formic acid resulted in higher scores than hydrochloric acid. Demineralization with EDTA yielded DNA amplification in 29 of 36 (81%) samples, whereas demineralization with either acid yielded amplification in only 2 of 72 (3%) samples. Although slightly more time-consuming and labor-intensive, tissue demineralization with EDTA results in superior morphology and is critical for polymerase chain reaction (PCR) amplification with the DNA extraction method described in this article.

The molybdenum- and tungsten-containing formate dehydrogenases from a variety of microorganisms catalyze the reversible interconversion of formate and CO2; several, in fact, function as CO2 reductases in the reverse direction under physiological conditions. CO2 reduction catalyzed by these enzymes occurs under mild temperature and pressure rather than the elevated conditions required for current industrial processes. Given the contemporary importance of remediation of atmospheric CO2 to address global warming, there has been considerable interest in the application of these enzymes in bioreactors. Equally important, understanding the detailed means by which these biological catalysts convert CO2 to formate, a useful and easily transported feedstock chemical, might also inspire the development of a new generation of highly efficient, biomimetic synthetic catalysts. Here we have examined the ability of the FdsDABG formate dehydrogenase from Cupriavidus necator to catalyze the exchange of solvent oxygen into product CO2 during the course of formate oxidation under single-turnover conditions. Negligible incorporation of 18O is observed when the experiment is performed in H218O, indicating that bicarbonate cannot be the immediate product of the enzyme-catalyzed reaction, as previously concluded. These results, in conjunction with the observation that the reductive half-reaction exhibits mildly acid-catalyzed rather than base-catalyzed chemistry, are consistent with a reaction mechanism involving direct hydride transfer from formate to the enzymes molybdenum center, directly yielding CO2. Our results are inconsistent with any mechanism in which the initial product formed on oxidation of formate is bicarbonate.

The exploration of novel hosts with the ability to assimilate formic acid, a C1 substrate that can be produced from renewable electrons and CO2, is of great relevance for developing novel and sustainable biomanufacturing platforms. Formatotrophs can use formic acid or formate as a carbon and/or reducing power source. Formatotrophy has typically been studied in neutrophilic microorganisms because formic acid toxicity increases in acidic environments below the pKa of 3.75 (25°C). Because of this toxicity challenge, utilization of formic acid as either a carbon or energy source has been largely unexplored in thermoacidophiles, species that possess the ability to produce a variety of metabolites and enzymes of high biotechnological relevance. Here we investigate the capacity of several thermoacidophilic archaea species from the Sulfolobales order to tolerate and metabolize formic acid. Metallosphaera prunae, Sulfolobus metallicus and Sulfolobus acidocaldarium were found to metabolize and grow with 1-2 mM of formic acid in batch cultivations. Formic acid was co-utilized by this species alongside physiological electron donors, including ferrous iron. To enhance formic acid utilization while maintaining aqueous concentrations below the toxicity threshold, we developed a bioreactor culturing method based on a sequential formic acid feeding strategy. By dosing small amounts of formic acid sequentially and feeding H2 as co-substrate, M. prunae could utilize a total of 16.3 mM of formic acid and grow to higher cell densities than when H2 was supplied as a sole electron donor. These results demonstrate the viability of culturing thermoacidophilic species with formic acid as an auxiliary substrate in bioreactors to obtain higher cell densities than those yielded by conventional autotrophic conditions. Our work underscores the significance of formic acid metabolism in extreme habitats and holds promise for biotechnological applications in the realm of sustainable energy production and environmental remediation.

In this study, we aimed to understand the potential role of the gut microbiome in the development of Alzheimers disease (AD). We took a multi-faceted approach to investigate this relationship. Urine metabolomics were examined in individuals with AD and controls, revealing decreased formate and fumarate concentrations in AD. Additionally, we utilised whole-genome sequencing (WGS) data obtained from a separate group of individuals with AD and controls. This information allowed us to create and investigate host-microbiome personalised whole-body metabolic models. Notably, AD individuals displayed diminished formate microbial secretion in these models. Additionally, we identified specific reactions responsible for the production of formate in the host, and interestingly, these reactions were linked to genes that have correlations with AD. This study suggests formate as a possible early AD marker and highlights genetic and microbiome contributions to its production. The reduced formate secretion and its genetic associations point to a complex connection between gut microbiota and AD. This holistic understanding might pave the way for novel diagnostic and therapeutic avenues in AD management.

The aminocarbonylation of alkenes is an efficient approach to synthesize important β-amino acid motifs. However, simple and convenient methods are still rare. Herein, we present a novel visible-light-mediated controllable three-component radical relay coupling of alkenes, alkyl formates and oxime esters. By the combination of hydrogen atom transfer and energy transfer processes, a series of β-amino esters could be obtained smoothly in one step under mild conditions. We expect that the approach can complement current methodologies for the synthesis of β-amino esters. [ABSTRACT FROM AUTHOR]

Secondary‐metals promotion is key to tune the CO2 hydrogenation performance of Rh‐based catalyst. We describe the addition of Cu or Co in TiO2 nanorods supported Rh catalyst (viz., RhMx/TiO2), showing significant impact on the CO2 hydrogenation activity and productivity. Cu addition can promote the partial hydrogenation to alcohols (methanol and ethanol), whereas Co led to the deep hydrogenation to alkanes (CH4, C2H6). Comparative time‐resolved in situ DRIFTS studies with H2/D2 isotopic exchange further reveal that both surface adsorbed CO* and formates could be the key reaction intermediates during the CO2 hydrogenation over RhMx/TiO2 (especially the RhCu2.5/TiO2), in which the interaction strength of CO* regulated by secondary‐metals addition was key to tune the reaction pathways and productivity. The findings suggested that rational design of active metal sites, for example the synergy between Rh and secondary‐metals, is highly needed to promote the CO insertion and CC coupling to produce ethanol. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: A visible‐light‐induced and efficient one‐pot synthesis of β‐hydroxysulfides from olefins, thiosulfonates and HCOOCs using an EDA complex strategy under air atmosphere at room temperature has been disclosed. A plausible radical involved mechanism is proposed. During the reaction process, formates play a crucial role: first, as donors in the EDA complex; second, as providers of the hydrogen source; and third, by generating CO2•– to reduce peroxide intermediates, leading to the formation of β‐hydroxysulfides. In contrast to the previously reported thiol‐oxygen co‐oxidation reactions, this simple and sustainable approach features mild reaction conditions, operational simplicity, odorless and excellent functional group tolerance. [ABSTRACT FROM AUTHOR]

An efficient palladium-catalyzed cascade cyclization/carbonylation of indoles with aryl formates to access ester-functionalized indolo[2,1-a]isoquinoline scaffolds has been developed. In addition, an asymmetric variant is also achieved using a chiral phosphine ligand, affording the indolo[2,1-a]isoquinoline products in good yields and enantioselectivities. [ABSTRACT FROM AUTHOR]

TiO2-supported Pd NPs-based materials were prepared following two distinct approaches: For the first set of materials 1–8, modification of the TiO2 support was performed prior to Pd NPs deposition, while the second set (9–15) was synthesized by deposition of modifiers over pre-synthesized Pd-PPh3/TiO2. These catalysts were applied in the hydrogenation of CO2 to formate, and their performance was compared with that of the unmodified Pd-PPh3/TiO2. Modification of the TiO2 support by organosilanes provided a beneficial effect in catalysis compared with the catalyst containing unmodified TiO2 or TiO2 modified by organophosphonic acids. In contrast, in most cases, the deposition of modifiers over previously synthesized Pd NPs supported on TiO2 was not beneficial to the activity of the catalyst. Interestingly, upon recycling, the first set of catalysts suffered a rapid decrease in activity, while the anchoring of modifiers over previously formed Pd NPs showed an improved stability (TON > 500 after the third recycling). [ABSTRACT FROM AUTHOR]

Herein, we report the hydrogenation of carbon dioxide to sodium formate catalyzed by low-valent molybdenum phosphine complexes. The 1,3-bis(diphenylphosphino)propane (DPPP)-based Mo complex was found to be an efficient catalyst in the presence of NaOH affording formate with a TON of 975 at 130 °C in THF/H2O after 24 h utilizing 40 bar (CO2 : H2 = 10 : 30) pressure. The complex was also active in the hydrogenation of sodium bicarbonate and inorganic carbonates to the corresponding formates. Mechanistic investigation revealed that the reaction proceeded via an intermediate formato complex. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: A Pd‐catalyzed regioselective hydroesterification of alkyl terminal olefins with aryl formates is described. A wide variety of linear carboxylic esters bearing various functional groups can be obtained in good yields with high regioselectivities under mild reaction conditions by using 1,2‐DTBPMB or (p‐F‐Ph)3P as ligand. The reaction process is operationally simple and requires no handling of toxic CO or strong acid. The resulting aryl esters can be readily converted to other carboxylic acid derivatives. [ABSTRACT FROM AUTHOR]

Indium-based oxides are promising electrocatalysts for producing formate via CO2 reduction reaction, in which *OCHO is considered the key intermediate. Here, we identified that the *COOH pathway could be preferential to produce formate on In2O3 of In/In2O3 heterojunction due to the synergistic effect of oxygen species and vacancy. Specifically, *CO2 and *COOH were observed on In2O3 and related to formate production by in situ Raman spectroscopy. The theoretical calculations further demonstrated that the energy barrier of the *COOH formation on In2O3 was decreased in the presence of oxygen vacancy, similar to or lower than that of the *OCHO formation on the In surface. As a result, a formate selectivity of over 90% was obtained on prepared In/In2O3 heterojunction with 343 ± 7 mA cm-2 partial current density. Furthermore, when using a Si-based photovoltaic as an energy supplier, 10.11% solar--to--fuel energy efficiency was achieved. [ABSTRACT FROM AUTHOR]

The escalating levels of atmospheric CO2, primarily attributed to human activities, underscore the urgent need for innovative solutions to mitigate environmental challenges. This study delves into the electrochemical reduction of CO2 as a promising avenue for sustainable carbon capture and utilization. Focused on the formation of formate (HCOO−/HCOOH), a high-value product, the research explores the integration of nonthermal plasma (NTP) with electrochemical processes—an approach rarely studied in existing literature. A comprehensive investigation involves varying parameters such as plasma discharging voltage, carrier gas, discharging mode, electrolysis voltage, polarity, and plasma type. The electrochemical tests employ a 10 wt.% Pd/C catalyst, and formate production is quantitatively analyzed using NMR. Results reveal that NTP significantly enhances CO2 reduction, with key factors influencing formate yield elucidated. The study reveals the complexity of CO2 electrochemical reduction, providing novel insights into the synergistic effects of NTP. These findings contribute to advancing sustainable technologies for CO2 utilization, paving the way for more efficient and environmentally friendly processes in the pursuit of a carbon-neutral future. [ABSTRACT FROM AUTHOR]

Salmonella enterica serovar Typhimurium induces intestinal inflammation to create a niche that fosters the outgrowth of the pathogen over the gut microbiota. Under inflammatory conditions, Salmonella utilizes terminal electron acceptors generated as byproducts of intestinal inflammation to generate cellular energy through respiration. However, the electron donating reactions in these electron transport chains are poorly understood. Here, we investigated how formate utilization through the respiratory formate dehydrogenase-N (FdnGHI) and formate dehydrogenase-O (FdoGHI) contribute to gut colonization of Salmonella. Both enzymes fulfilled redundant roles in enhancing fitness in a mouse model of Salmonella-induced colitis, and coupled to tetrathionate, nitrate, and oxygen respiration. The formic acid utilized by Salmonella during infection was generated by its own pyruvate-formate lyase as well as the gut microbiota. Transcription of formate dehydrogenases and pyruvate-formate lyase was significantly higher in bacteria residing in the mucus layer compared to the lumen. Furthermore, formate utilization conferred a more pronounced fitness advantage in the mucus, indicating that formate production and degradation occurred predominantly in the mucus layer. Our results provide new insights into how Salmonella adapts its energy metabolism to the local microenvironment in the gut. IMPORTANCE Bacterial pathogens must not only evade immune responses but also adapt their metabolism to successfully colonize their host. The microenvironments encountered by enteric pathogens differ based on anatomical location, such as small versus large intestine, spatial stratification by host factors, such as mucus layer and antimicrobial peptides, and distinct commensal microbial communities that inhabit these microenvironments. Our understanding of how Salmonella populations adapt its metabolism to different environments in the gut is incomplete. In the current study, we discovered that Salmonella utilizes formate as an electron donor to support respiration, and that formate oxidation predominantly occurs in the mucus layer. Our experiments suggest that spatially distinct Salmonella populations in the mucus layer and the lumen differ in their energy metabolism. Our findings enhance our understanding of the spatial nature of microbial metabolism and may have implications for other enteric pathogens as well as commensal host-associated microbial communities.

[Display omitted] The solid solutions of Zr 1– x Sc x O 2– δ (0 < x ≤ 0.1) were prepared using a precursor technology, and their structural, optical, and photocatalytic characteristics were studied. Mixed formates synthesized by an original method were used as precursors. Scandium favored the formation of ZrO 2 in tetragonal syngony and increased its photoactivity in the UV range. [ABSTRACT FROM AUTHOR]

A detailed operando DRIFTS study on the CO2 Fischer‐Tropsch reaction with K‐promoted Fe/YZrOx catalysts was performed to investigate the influence of this modification on the catalytic performance in the formation of lower olefins as well as higher hydrocarbons and to gain insights into mechanistic aspects. Catalytic testing revealed an enhanced formation of olefins and hydrocarbons by adding potassium to the catalysts, while spectroscopic studies revealed various stable adsorbates and intermediates such as monodentate carbonates, bicarbonates, formates, formyl, and methoxy on the surface of the K‐promoted Fe/YZrOx catalysts compared to the unpromoted one. Based on gas‐feed switching experiments and statistical analysis of literature IR data regarding Fe‐containing catalysts, it was found that carbonate species interacting with H2 are transformed to higher hydrocarbons and methane via formate and formyl formation, while bicarbonate species are decomposed accompanied by the formation of CO, which then further reacts to form formate or formyl and finally hydrocarbons. [ABSTRACT FROM AUTHOR]

An efficient palladium-catalyzed carbonylation of aryl fluorosulfates with aryl formates for the facile synthesis of esters was developed. The cross-coupling reactions proceeded effectively in the presence of a palladium catalyst, phosphine ligand, and triethylamine in DMF to produce the corresponding esters in moderate to good yields. Of note, functionalities or substituents, such as nitro, cyano, methoxycarbonyl, trifluoromethyl, methylsulfonyl, trifluoromethoxy, fluoro, chloro, bromo, methyl, methoxy, N,N-dimethyl, and [1,3]dioxolyl, were well-tolerated in the reactions, which could be kept for late-stage modification. The reactions employing readily available and relatively robust aryl fluorosulfates as coupling electrophiles could potentially serve as an attractive alternative to traditional cross-couplings with the use of aryl halides and pseudohalides as substrates. [ABSTRACT FROM AUTHOR]

Gas-phase reactions involving simplest Criegee intermediate (CH2OO) have been the current hot topic due to its vital role in atmospheric chemistry. In this study, high-level ab initio calculations are used to investigate the energetics and kinetics for the reaction of CH2OO + ROH → ROCHO + H2O (R=CH3, CH3CH2 and (CH3)2CH). Energies of the stationary points are computed at the CCSD(T)/M06-2X/6-311++G(3d,3pd)//M06-2X/6-311++G(3d,3pd) level of theory. Reaction is going through a 1,2-addition and water elimination step leading to the formation of alkoxymethyl hydroperoxides and alkyl formates, respectively. The barrier heights for the 1,2-addition step with methanol, ethanol, and isopropanol were found to be − 3.1, − 3.7, and − 4.8 kcal mol−1, and water elimination steps were found to be 2.2, 1.5, and 1.6 kcal mol−1, respectively, relative to the energies of the starting reactants. The rate constants for addition and elimination channels were calculated using canonical variational transition state theory in conjugation with small-curvature tunneling and the interpolated single point energy method between the temperature range of 200 and 500 K. In addition, the thermochemistry analysis indicates that addition and elimination channels are thermodynamically feasible and the formation of alkyl formates is entropically more favored when compared to the formation of alkoxymethyl hydroperoxide along the reaction path in the potential energy surface. The pressure-dependent microcanonical rate constants for both addition and elimination channels were also estimated using the Rice–Ramsperger–Kassel–Marcus theory and discussed in this study. [ABSTRACT FROM AUTHOR]

A method for the synthesis of propargylic formates from propargylic alcohols and sodium chlorodifluoroacetate is reported. In the reaction, sodium chlorodifluoroacetate is used as a difluorocarbene precursor and a formylating reagent to provide a carbonyl source, while the triple bond of propargylic alcohols is not involved. The method shows convenient operation, good functional group tolerance and high site‐selectivity under mild reaction conditions. [ABSTRACT FROM AUTHOR]

Dehalococcoides mccartyi strains harboring vinyl chloride (VC) reductive dehalogenase (RDase) genes are keystone bacteria for VC detoxification in groundwater aquifers, and bioremediation monitoring regimens focus on D. mccartyi biomarkers. We isolated a novel anaerobic bacterium, Candidatus Dehalogenimonas etheniformans strain GP, capable of respiratory dechlorination of VC to ethene. This bacterium couples formate and hydrogen (H2) oxidation to the reduction of trichloro-ethene (TCE), all dichloroethene (DCE) isomers, and VC with acetate as the carbon source. Cultures that received formate and H2 consumed the two electron donors concomitantly at similar rates. A 16S rRNA gene-targeted quantitative PCR (qPCR) assay measured growth yields of (1.2 ± 0.2) × 108 and (1.9 ± 0.2) × 108 cells per μmol of VC dechlorinated in cultures with H2 or formate as electron donor, respectively. About 1.5-fold higher cell numbers were measured with qPCR targeting cerA, a single-copy gene encoding a putative VC RDase. A VC dechlorination rate of 215 ± 40 μmol L-1 day-1 was measured at 30°C, with about 25% of this activity occurring at 15°C. Increasing NaCl concentrations progressively impacted VC dechlorination rates, and dechlorination ceased at 15 g NaCl L-1. During growth with TCE, all DCE isomers were intermediates. Tetrachloroethene was not dechlorinated and inhibited dechlorination of other chlorinated ethenes. Carbon monoxide formed and accumulated as a metabolic by-product in dechlorinating cultures and impacted reductive dechlorination activity. The isolation of a new Dehalogenimonas species able to effectively dechlorinate toxic chlorinated ethenes to benign ethene expands our understanding of the reductive dechlorination process, with implications for bioremediation and environmental monitoring. IMPORTANCE Chlorinated ethenes are risk drivers at many contaminated sites, and current bioremediation efforts focus on organohalide-respiring Dehalococcoides mccartyi strains to achieve detoxification. We isolated and characterized the first non-Dehalococcoides bacterium, Candidatus Dehalogenimonas etheniformans strain GP, capable of metabolic reductive dechlorination of TCE, all DCE isomers, and VC to environmentally benign ethene. In addition to hydrogen, the new isolate utilizes formate as electron donor for reductive dechlorination, providing opportunities for more effective electron donor delivery to the contaminated subsurface. The discovery that a broader microbial diversity can achieve detoxification of toxic chlorinated ethenes in anoxic aquifers illustrates the potential of naturally occurring microbes for biotechnological applications.

CO2 catalytic hydrogenation to formate was achieved (TONmax=ca. 3800) in the presence of the neutral, halide‐free, coordinatively saturated tris(carbonyl) manganese pincer‐type complex [Mn(PNP)(CO)3], bearing a diarylamido pincer‐type PNP ligand, using DBU as base and LiOTf as Lewis acid additive, under mild reaction conditions (60 bar, 80 °C). DFT calculations suggest that the precatalyst activation key step occurs by intermolecular, base assisted dihydrogen heterolytic splitting rather than by the expected ligand‐assisted intramolecular MLC‐type mechanism. [ABSTRACT FROM AUTHOR]

Cu(I)-Hydrido complexes supported by dibenzo[b,f]azepinyl P-alkene hybrid ligands and stabilized by electrostatic interactions in a Cu–H⋯KCl⋯BR3 arrangement can be trapped with CO2 at low temperature to afford Cu(I)-formates. The complexes are isolable with and without a pendant BEt3 group and show strong Cu–O and weak B–O interactions. [ABSTRACT FROM AUTHOR]

Methylomicrobium album BG8 is an aerobic methanotrophic bacterium with promising features as a microbial cell factory for the conversion of methane to value-added chemicals. However, the lack of a genome-scale metabolic model (GEM) of M. album BG8 has hindered the development of systems biology and metabolic engineering of this methanotroph. To fill this gap, a high-quality GEM was constructed to facilitate a system-level understanding of the biochemistry of M. album BG8. Flux balance analysis, constrained with time-series data derived from experiments with various levels of methane, oxygen, and biomass, was used to investigate the metabolic states that promote the production of biomass and the excretion of carbon dioxide, formate, and acetate. The experimental and modeling results indicated that M. album BG8 requires a ratio of ∼1.5:1 between the oxygen- and methane-specific uptake rates for optimal growth. Integrative modeling revealed that at ratios of  >2:1 oxygen-to-methane uptake flux, carbon dioxide and formate were the preferred excreted compounds, while at ratios of

Formate has great potential to function as a feedstock for biorefineries because it can be sustainably produced by a variety of processes that don't compete with agricultural production. However, naturally formatotrophic organisms are unsuitable for large-scale cultivation, difficult to engineer, or have inefficient native formate assimilation pathways. Thus, metabolic engineering needs to be developed for model industrial organisms to enable efficient formatotrophic growth. Here, we build a prototype synthetic formate utilizing bacterial microcompartment (sFUT) encapsulating the oxygen-sensitive glycyl radical enzyme pyruvate formate lyase and a phosphate acyltransferase to convert formate and acetyl-phosphate into the central biosynthetic intermediate pyruvate. This metabolic module offers a defined environment with a private cofactor coenzyme A that can cycle efficiently between the encapsulated enzymes. To facilitate initial design-build-test-refine cycles to construct an active metabolic core, we used a "wiffleball" architecture, defined as an icosahedral bacterial microcompartment (BMC) shell with unoccupied pentameric vertices to freely permit substrate and product exchange. The resulting sFUT prototype wiffleball is an active multi enzyme synthetic BMC functioning as platform technology.

There is widespread interest in the hydrogenation of CO2 to produce high‐energy substances such as formic acid. Herein, ruthenium trichloride was immobilized on porous phosphine polymers (Ru/KAPs‐Ph‐PPh3) and gave excellent catalytic activity in the hydrogenation of CO2 to produce formate. With the assistance of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU), a high turnover number (TON) of up to 1470000 was obtained in 12 hours at 120 °C and a total pressure of 6 MPa (P(H2)/P(CO2)=1 : 1), with average TOFs of 122500 h−1. Moreover, the catalyst can be easily recovered by filtration with acceptable catalytic effectiveness. [ABSTRACT FROM AUTHOR]

• V Bi ″ ′ V 0 · · · V bi ″ ′ vacancy associates in BiOBr precursors converted into dual V Bi 0 vacancy sites during CO 2 ER. • Dual V Bi 0 vacancy associates enhance the CO 2 ER activity and selectivity of Bi° catalysts. • Bi VNS achieves a remarkable j HCOO −up to 755 mA/cm2 in a flow cell. • Dual V Bi 0 vacancy associates regulate the adsorption strength of the *OCHO intermediate. The electrocatalytic reduction of carbon dioxide (CO 2 ER) into formate presents a compelling solution for mitigating dependence on fossil energy and green utilization of CO 2. Bismuth (Bi) has been gaining recognition as a promising catalyst material for the CO 2 ER to formate. The performance of Bi catalysts (named as Bi-V) can be significantly improved when they possess single metal atom vacancy. However, creating larger-sized metal atom vacancies within Bi catalysts remains a significant challenge. In this work, Bi nanosheets with dual V Bi 0 vacancy (Bi-DV) were synthesized utilizing in situ electrochemical transformation, using BiOBr nanosheets with triple vacancy associates (V Bi ″ ′ V O · · V Bi ″ ′ , V Bi ″ ′ and V O · · denote the Bi3+ and O2− vacancy, respectively) as a template. The obtained Bi-DV achieved higher CO 2 ER activity than Bi-V, showing Faradaic efficiency for formate production of >92% from -0.9 to -1.2 V RHE in an H-type cell, and the partial current density of formate reached up to 755 mA/cm2 in a flow cell. The comprehensive characterizations coupled with density functional theory calculations demonstrate that the dual V Bi 0 vacancy on the surface of Bi-DV expedite the reaction kinetics toward CO 2 ER, by reducing the thermodynamic barrier of *OCHO intermediate formation. This research provides critical insights into the potential of large atom vacancies to enhance electrocatalysis performance. [Display omitted] [ABSTRACT FROM AUTHOR]

Mitochondrial carriers (MCs) mediate the passage of small molecules across the inner mitochondrial membrane (IMM), enabling regulated crosstalk between compartmentalized reactions. Despite MCs representing the largest family of solute carriers in mammals, most have not been subjected to a comprehensive investigation, limiting our understanding of their metabolic contributions. Here, we functionally characterize SFXN1, a member of the non-canonical, sideroflexin family. We find that SFXN1, an integral IMM protein with an uneven number of transmembrane domains, is a TIM22 complex substrate. SFXN1 deficiency leads to mitochondrial respiratory chain impairments, most detrimental to complex III (CIII) biogenesis, activity, and assembly, compromising coenzyme Q levels. The CIII dysfunction is independent of one-carbon metabolism, the known primary role for SFXN1 as a mitochondrial serine transporter. Instead, SFXN1 supports CIII function by participating in heme and α-ketoglutarate metabolism. Our findings highlight the multiple ways that SFXN1-based amino acid transport impacts mitochondrial and cellular metabolic efficiency.

Recently, we have investigated the amino acid L‐lysine promoted CO2 capture and in‐situ hydrogenation to produce formate applying ruthenium‐ and manganese‐based catalysts (Chem. Sci. 2021, 12, 6020, Nature Energy2022, 7, 438). Noteworthy, following this process CO2 can be captured from ambient air and directly converted to formate (TON>50,000). In this Comment, we report how hydrochloride impurities in the amino acid affect the CO2 capture efficiency and therewith lead to an ostensibly different behaviour of D‐ and L‐lysine in the CO2 capture. The results demonstrate the importance of careful analysis of all educts. [ABSTRACT FROM AUTHOR]

Cu/ZrO2 is a promising catalyst for the hydrogenation of CO2 to methanol. Reaction pathways involving formates or hydroxycarbonyls have been proposed. We show here that three different types of formates can be observed under reaction conditions at 220 °C and 3 bar, one being located on metallic Cu and two others being bound to ZrO2. The surface concentrations of formates were determined through calibration curves and their reactivity measured during chemical transient experiments. The Cu‐bound formate represented only about 7 % of surface formates, but exhibited a higher reactivity and was found to be the only formate that could account for all the production of methanol. Copper is thus not there only to activate H2, but also bears other crucial intermediates. This work reemphasizes that fully quantitative IR analyses and transient methods are required to unravel the role of surface species. [ABSTRACT FROM AUTHOR]

Cu/ZrO2 is a promising catalyst for the hydrogenation of CO2 to methanol. Reaction pathways involving formates or hydroxycarbonyls have been proposed. We show here that three different types of formates can be observed under reaction conditions at 220 °C and 3 bar, one being located on metallic Cu and two others being bound to ZrO2. The surface concentrations of formates were determined through calibration curves and their reactivity measured during chemical transient experiments. The Cu‐bound formate represented only about 7 % of surface formates, but exhibited a higher reactivity and was found to be the only formate that could account for all the production of methanol. Copper is thus not there only to activate H2, but also bears other crucial intermediates. This work reemphasizes that fully quantitative IR analyses and transient methods are required to unravel the role of surface species. [ABSTRACT FROM AUTHOR]

Cu/ZrO2 is a promising catalyst for the hydrogenation of CO2 to methanol. Reaction pathways involving formates or hydroxycarbonyls have been proposed. We show here that three different types of formates can be observed under reaction conditions at 220 °C and 3 bar, one being located on metallic Cu and two others being bound to ZrO2. The surface concentrations of formates were determined through calibration curves and their reactivity measured during chemical transient experiments. The Cu‐bound formate represented only about 7 % of surface formates, but exhibited a higher reactivity and was found to be the only formate that could account for all the production of methanol. Copper is thus not there only to activate H2, but also bears other crucial intermediates. This work reemphasizes that fully quantitative IR analyses and transient methods are required to unravel the role of surface species. [ABSTRACT FROM AUTHOR]

Cu/ZrO2 is a promising catalyst for the hydrogenation of CO2 to methanol. Reaction pathways involving formates or hydroxycarbonyls have been proposed. We show here that three different types of formates can be observed under reaction conditions at 220 °C and 3 bar, one being located on metallic Cu and two others being bound to ZrO2. The surface concentrations of formates were determined through calibration curves and their reactivity measured during chemical transient experiments. The Cu‐bound formate represented only about 7 % of surface formates, but exhibited a higher reactivity and was found to be the only formate that could account for all the production of methanol. Copper is thus not there only to activate H2, but also bears other crucial intermediates. This work reemphasizes that fully quantitative IR analyses and transient methods are required to unravel the role of surface species. [ABSTRACT FROM AUTHOR]

The increase in anthropogenic CO2 concentrations and associated environmental issues have demanded the development of technologies for CO2 utilization. Among various potential solutions to decrease CO2 emissions and achieve carbon neutrality, the recycling of post-combustion CO2 into value-added chemicals and fuels is considered one of the most economically attractive processes. In this regard, due to its large global demand and versatile applications in the chemical and energy sectors, methanol serves as the most appealing target for the chemical utilization of CO2. However, direct hydrogenation of CO2 to MeOH has proved challenging due to selectivity issues and high energy input, mainly dependent on CO2-emitting fossil energy sources. To address these challenges, an alternative indirect CO2-to-MeOH methodology has been proposed, which involves the hydrogenation of CO2 via the intermediate formation of well-known CO2 derivatives, such as formates, carbonates, formamides, carbamates, and urea derivatives. Homogeneous transition metal catalysts have been at the center of this research avenue, potentially allowing for more selective and low-temperature alternative routes from CO2 to MeOH. This review aims to highlight the advances and challenges in homogeneous transition metal-catalyzed hydrogenation of major CO2 derivatives to MeOH. Special attention is paid to the mechanisms of such transformations. [ABSTRACT FROM AUTHOR]

Ion–molecule reactions between the neutral ethyl- (EF), isopropyl- (IF), t-butyl- (TF) and phenyl formate (PF) and proton-bound water clusters W2H+ and W3H+ (W = H2O) showed that the major reaction product is water loss from the initial encounter complex, followed ultimately by the formation of the protonated formate. Collision-induced dissociation breakdown curves of the formate–water complexes were obtained as a function of collision energy and modeled to extract relative activation energies for the observed channels. Density functional theory calculations (B3LYP/6-311+G(d,p)) of the water loss reactions were consistent with reactions having no reverse energy barrier in each case. Overall, the results indicate that the interaction of formates with atmospheric water can form stable encounter complexes that will dissociate by sequential water loss to form protonated formates. [ABSTRACT FROM AUTHOR]

The synthesis of two series of catalysts based on ligand‐capped supported Pd nanoparticles was carried out using a simple procedure and the resulting materials were tested in the formate synthesis. Within these series, PPh3 revealed the most appropriate stabilizing ligand while TiO2 was the most efficient support for these catalysts. The hydrogenation of CO2 was carried out under mild reaction conditions (1.8 MPa CO2, 1.8 MPa H2, 60 °C) using water as solvent and in the presence of a base, providing excellent selectivity towards formates with a TON of 1032 (TOF of 69 h−1, [HCOOK]=1.1 mol/l). [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the in vitro antimicrobial activity of several organic acids and their derivatives against Gram-positive (G+) and Gram-negative (G-) bacteria. Butyric acid, valeric acid, monopropionin, monobutyrin, monovalerin, monolaurin, sodium formate, and ProPhorce-a mixture of sodium formate and formic acid (40:60 w/v)-were tested at 8 to 16 concentrations from 10 to 50,000 mg/L. The tested bacteria included G- bacteria (Escherichia coli, Salmonella enterica Typhimurium, and Campylobacter jejuni) and G+ bacteria (Enterococcus faecalis, Clostridium perfringens, Streptococcus pneumoniae, and Streptococcus suis). Antimicrobial activity was expressed as minimum inhibitory concentration (MIC) of tested compounds that prevented growth of tested bacteria in treated culture broth. The MICs of butyric acid, valeric acid, and ProPhorce varied among bacterial strains with the lowest MIC of 500-1000 mg/L on two strains of Campylobacter. Sodium formate at highest tested concentrations (20,000 mg/L) did not inhibit the growth of Escherichia coli, Salmonella Typhimurium, and Enterococcus faecalis, but sodium formate inhibited the growth of other tested bacteria with MIC values from 2000 to 18,800 mg/L. The MIC values of monovalerin, monolaurin, and monobutyrin ranged from 2500 to 15,000 mg/L in the majority of bacterial strains. Monopropionin did not inhibit the growth of all tested bacteria, with the exception that the MIC of monopropionin was 11,300 mg/L on Clostridia perfringens. Monolaurin strongly inhibited G+ bacteria, with the MIC value of 10 mg/L against Streptococcus pneumoniae. The MIC tests indicated that organic acids and their derivatives exhibit promising antimicrobial effects in vitro against G- and G+ bacteria that are resistant to antimicrobial drugs. The acid forms had stronger in vitro antimicrobial activities than ester forms, except that the medium chain fatty acid ester monolaurin exhibited strong inhibitory effects on G+ bacteria.

Direct biocatalytic conversion of CO2 to formic acid is an attractive means of reversibly storing energy in chemical bonds. Formate dehydrogenases (FDHs) are a heterogeneous group of enzymes that catalyze the oxidation of formic acid to carbon dioxide, generating two protons and two electrons. Several FDHs have recently been reported to catalyze the reverse reaction, i.e., the reduction of carbon dioxide to formic acid, under appropriate conditions. The main challenges with these enzymes are relatively low rates of CO2 reduction and high oxygen sensitivity. Our earlier studies (Yu et al. (2017) J. Biol. Chem. 292, 16872-16879) have shown that the FdsABG formate dehydrogenase from Cupriavidus necator is able to effectively catalyze the reduction of CO2, using NADH as a source of reducing equivalents, with a good oxygen tolerance. On the basis of this result, we have developed a highly thermodynamically efficient and cost-effective biocatalytic process for the transformation of CO2 to formic acid using FdsABG. We have  cloned the full-length soluble formate dehydrogenase (FdsABG) from C. necator and expressed it in Escherichia coli with a His-tag fused to the N terminus of the FdsG subunit; this overexpression system has greatly simplified the FdsABG purification process. Importantly, we have also combined this recombinant C. necator FdsABG with another enzyme, glucose dehydrogenase, for continuous regeneration of NADH for CO2 reduction and demonstrated that the combined system is highly effective in reducing CO2 to formate. The results indicate that this system shows significant promise for the future development of an enzyme-based system for the industrial reduction of CO2.

We report an approach to conducting the hydroaminomethylation of diverse α-olefins with a wide range of alkyl, aryl, and heteroarylamines at relatively low temperatures (70-80 °C) and pressures (1.0-3.4 bar) of synthesis gas. This approach is based on simultaneously using two distinct catalysts that are mutually compatible. The hydroformylation step is catalyzed by a rhodium diphosphine complex, and the reductive amination step, which is conducted as a transfer hydrogenation with aqueous, buffered sodium formate as the reducing agent, is catalyzed by a cyclometallated iridium complex. By adjusting the ratio of CO to H2 , we conducted the reaction at one atmosphere of gas with little change in yield. A diverse array of olefins and amines, including hetreroarylamines that do not react under more conventional conditions with a single catalyst, underwent hydroaminomethylation with this new system, and the pharmaceutical ibutilide was prepared in higher yield and under milder conditions than with a single catalyst.

Electrocatalytic CO2 reduction reaction (eCO2RR) has significant relevance to settle the global energy crisis and abnormal climate problem via mitigating the excess emission of waste CO2 and producing high-value-added chemicals. Currently, eCO2RR to formic acid or formate is one of the most technologically and economically viable approaches to realize high-efficiency CO2 utilization, and the development of efficient electrocatalysts is very urgent to achieve efficient and stable catalytic performance. In this review, the recent advances for twodimensional bismuth-based nanosheets (2D Bi-based NSs) electrocatalysts are concluded from both theoretical and experimental perspectives. Firstly, the preparation strategies of 2D Bi-based NSs in aspects to precisely control the thickness and uniformity are summarized. In addition, the electronic regulation strategies of 2D Bi-based NSs are highlighted to gain insight into the effects of the structure-property relationship on facilitating CO2 activation, improving product selectivity, and optimizing carrier transport dynamics. Finally, the considerable challenges and opportunities of 2D Bi-based NSs are discussed to lighten new directions for future research of eCO2RR. [ABSTRACT FROM AUTHOR]

Easily accessible via a simple esterification of alcohols with formic acid, alkyl formates are used as a novel class of transfer hydroalkylation reagents, CO2 acting as a traceless linker. As a proof‐of‐concept, their reactivity in the transfer hydroalkylation of imines is investigated, using a ruthenium‐based catalyst and LiI as promoter to cleave the C−O σ‐bond of the formate scaffold. Providing tertiary amines, the reaction displays a divergent regioselectivity compared to previously reported transfer hydroalkylation strategies. [ABSTRACT FROM AUTHOR]

Preliminary transformation into sulfonium salts by an electrophilic reaction with alkyl formates in the presence of trifluoromethanesulfonic acid is proposed for the study and analysis of non-polar organic sulfides by matrix-assisted laser desorption/ionization (MALDI). The test samples are thiabicyclanes with different positions of the sulfur atom and methyl substituents (2- and 3-thiabicyclo[4.4.0] decanes, 7- and 8-thiabicyclo [4.3.0] nonanes). The reaction used provide quantitative S-alkylation under mild conditions. In MALDI mass spectra of sulfonium salts, only peaks of corresponding sulfonium cations were observed, the masses of which corresponded to the sum of molecular weights of the sulfide and the increment of the introduced alkyl group. Drastic qualitative and quantitative differences were found and interpreted in the mass spectra recorded in the collision-induced dissociation mode for regio-isomeric sulfonium cations. [ABSTRACT FROM AUTHOR]

Mammalian folate metabolism is comprised of cytosolic and mitochondrial pathways with nearly identical core reactions, yet the functional advantages of such an organization are not well understood. Using genome-editing and biochemical approaches, we find that ablating folate metabolism in the mitochondria of mammalian cell lines results in folate degradation in the cytosol. Mechanistically, we show that QDPR, an enzyme in tetrahydrobiopterin metabolism, moonlights to repair oxidative damage to tetrahydrofolate (THF). This repair capacity is overwhelmed when cytosolic THF hyperaccumulates in the absence of mitochondrially produced formate, leading to THF degradation. Unexpectedly, we also find that the classic antifolate methotrexate, by inhibiting its well-known target DHFR, causes even more extensive folate degradation in nearly all tested cancer cell lines. These findings shed light on design features of folate metabolism, provide a biochemical basis for clinically observed folate deficiency in QDPR-deficient patients, and reveal a hitherto unknown and unexplored cellular effect of methotrexate.

BackgroundFormate is an important metabolite that serves as a donor of one-carbon groups to the intracellular tetrahydrofolate pool. However, little is known of its circulating concentrations or of their determinants.ObjectiveThis study aimed to define formate concentrations and their determinants in a healthy young population.DesignSerum formate was measured in 1701 participants from the Trinity Student Study. The participants were men and women, aged 18 to 28 y, enrolled at Trinity College, Dublin. Formate concentrations were compared with other one-carbon metabolites, vitamin status, potential formate precursors, genetic polymorphisms, and lifestyle factors.ResultsSerum formate concentrations ranged from 8.7 to 96.5 µM, with a mean of 25.9 µM. Formate concentrations were significantly higher in women than in men; oral contraceptive use did not further affect them. There was no effect of smoking or of alcohol ingestion, but the TT genotype of the methylenetetrahydrofolate reductase (MTHFR) 677C→T (rs1801133) polymorphism was associated with a significantly decreased formate concentration. Formate was positively associated with potential metabolic precursors (serine, methionine, tryptophan, choline) but not with glycine. Formate concentrations were positively related to serum folate and negatively related to serum vitamin B-12.ConclusionsFormate concentrations were sensitive to the concentrations of metabolic precursors. In view of the increased susceptibility of women with the TT genotype of MTHFR to give birth to infants with neural tube defects as well as the effectiveness of formate supplementation in decreasing the incidence of folate-resistant neural tube defects in susceptible mice, it will be important to understand how this genotype decreases the serum formate concentration. This trial was registered at www.clinicaltrials.gov as NCT03305900.

Soluble epoxide hydrolase (sEH) inhibition is reported to elevate endogenous epoxyeicosatrienoic acids (EET's), which are known to play an important role in neuroprotection by inhibiting oxidative stress and neuroinflammation. In the present study, PTUPB, a dual inhibitor of sEH and COX-2, has been tested for its antiparkinson activity against rotenone (ROT) induced neurodegeneration in Drosophila model of Parkinson's disease (PD). To determine the efficacy and brain bioavailability of PTUPB a simple, rapid and sensitive LC-MS/MS method was developed and validated for the estimation of PTUPB (Method-I), dopamine (DA) and its metabolites (Method-II) in fly head. Mass spectrometric acquisitions of analytes signals were performed in positive and negative electron spray ionization MRM mode by monitoring the daughter ions. The isocratic elution using formic acid (0.1% v/v) and acetonitrile (20:80v/v) (for method I), and acetic acid (0.1% v/v) and methanol (for method II) on Jones C18 was carried out to achieve the separation. The results of brain PTUPB, DA and its metabolites estimation shows a dose dependent increase in PTUPB concentration and a dose dependent prevention of ROT induced changes in DA and its metabolites levels (p

Dielectric relaxation spectra of three members of the alkylammonium formate family of protic ionic liquids (PILs), namely, ethylammonium formate (EAF), n-butylammonium formate (BuAF), and n-pentylammonium formate (PeAF), as well as the pseudo-PIL triethylamine + formic acid (molar ratio 1:2; TEAF) have been studied over a wide frequency (50 MHz to 89 GHz) and temperature range (5–65 °C), complemented by measurements of their density, viscosity, and conductivity. It turned out that the dominating relaxation of EAF, BuAF, and PeAF arises from both cation and anion reorientations which are synchronized in their dynamics due to hydrogen bonding. Amplitudes and relaxation times of this mode reflect the—compared to nitrate—different nature of H bonding between the formate anion and ethylammonium cation, as well as increasing segregation of the PIL structure into polar and non-polar domains. The TEAF data suggest that its dominating relaxation is due to the rotation of the complex triethylamine⋅(formic acid)2 in which no significant proton transfer to an ion pair occurred. Weak dissociation of this complex into ions was postulated to account for the high conductivity of TEAF. [ABSTRACT FROM AUTHOR]

Protected 2-O-benzyolated glycosyl formates were synthesized in one-step from the corresponding orthoester using formic acid as the sole reagent. Glucopyranosyl, mannopyranosyl and galactopyranosyl donors were synthesized and their glycosylation properties studied using model glycosyl acceptors of varied steric bulk and reactivity. Bismuth triflate was the preferred catalyst and KPF6 was used as an additive. The 1,2-trans-selectivities resulting from neighboring-group participation were excellent and the glycosylations were generally high-yielding. [ABSTRACT FROM AUTHOR]

Tailings represent a significant risk to the environment globally, but very little is known about the composition of the near-surface air. We conducted laboratory experiments to determine the sizes of the particles and the chemical composition of the flow above the mine waste. A condensate of vapor–gas flow was collected in parallel with particle control by an aerosol diffusion spectrometer (ADS). We reveal that there were no aerosol particles bigger than 3 nm in the flow. The collected condensate contained chemical elements, ions of sulfates, chlorides, phosphates, and formates and a wide range of sulfur-, selenium-, and carbon-containing gases. The main findings of the study are the presence of the metals Zn, Cu, Fe, Al, Cd, Ni, and Ba and the metalloids As, Sb, Se, Ag, Co, Ti, and V in the true-gas phase or in the form of particles smaller than 3 nm in the air above the mine tailings. The surprising fact is that the migration of metals and metalloids in a true-gas form or in ultrafine particles (<3 nm) is possible, which opens up a new research direction on the volatile forms of chemical elements in various climatic conditions and their bioavailability and toxicity. [ABSTRACT FROM AUTHOR]

By slow hydrolysis of solutions of [Eu(DMF)8]I3 or [Nd(DMF)8]I3 in dimethylformamide (DMF), single crystals of the coordination compounds [ RE 12(DMF)24 (HCOO)8(OH)16]I3·4DMF (RE = Eu, Nd) were obtained. Both compounds crystallise isotypically in a tetragonal structure with space group I 422 (No. 97, Z = 2, a = 21.881(3), 21.6340(10) and c = 20.873(2), 21.0612(9) Å for Nd and Eu compounds, respectively). The crystal structure shows a [ RE 12O56] core unit with O atoms from formate and hydroxide anions μ3-bridging the metal centres. The dodecanuclear cationic units are arranged in a body-centred packing topology, surrounded by iodide anions in a β cage pattern. Rietveld refinement confirmed the structure model, and the presence of hydroxide anions was shown by FT-IR spectroscopy. Susceptibility measurements on the Nd compound showed paramagnetic behaviour and a temperature dependence of μ eff typical for trivalent Nd cations. Two dodecanuclear coordination compounds of trivalent rare earth metal cations show short interatomic RE–RE distances due to bridging O atoms from hydroxide and formate anions. Magnetic susceptibility and structural details suggest single molecule magnetic behaviour. [ABSTRACT FROM AUTHOR]

The objective of this exploratory study was to assess the changes on lipidome and metabolome profiling of Longissimus lumborum bull muscle with different ultimate pH (pHu) and aging periods. The bull muscles classified as normal, intermediate, or high pHu were collected from a Brazilian commercial slaughterhouse, cut into steaks, individually vacuum-packaged, and aged for 3 days (3-d) or 21 days (21-d) at 2 °C. Muscle extracts were analyzed for the profiles of both lipids, by mass spectrometry (via direct flow-injection), and metabolites, by nuclear magnetic resonance, with downstream multivariate data analysis. As major results, pairwise comparisons identified C12:0 and C14:0 acylcarnitines as potential biomarkers of the intermediate pHu-muscle, which are related to lipid catabolism for alternative energy metabolism and indicate less protein breakage postmortem. Interestingly, the concentration of arginine at early postmortem aging (3-d) may influence the previously reported improved tenderness in normal and high pHu-muscles. Moreover, upregulation of fumarate, formate, and acetate with increased pHu muscle at 21-d aging indicate more intense tricarboxylic acid cycle, amino acid degradation, and pyruvate oxidation by reactive oxygen species, respectively. These three compounds (fumarate, formate, and acetate) discriminated statistically the muscle with high pHu at 21-d aging. The normal pHu-muscle showed higher concentrations of glycogenolysis and glycolysis metabolites, including glucose, mannose, and pyruvate. Hence, our results enhance knowledge of postmortem biochemical changes of beef within different pHu groups aged up to 21 days, which is essential to understand the mechanisms underpinning bull meat quality changes., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Carmen Josefina Contreras Castillo reports financial support was provided by State of Sao Paulo Research Foundation. Alan Giovanini de Oliveira Sartori reports financial support was provided by State of Sao Paulo Research Foundation. If there are other authors, they 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.)