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Journal of Zhejiang University....Methane is the simplest hydrocarbon, consisting of one carbon atom and four hydrogen atoms. It is abundant in marsh gas, livestock rumination, and combustible ice.... (Review)
Review
Methane is the simplest hydrocarbon, consisting of one carbon atom and four hydrogen atoms. It is abundant in marsh gas, livestock rumination, and combustible ice. Little is known about the use of methane in human disease treatment. Current research indicates that methane is useful for treating several diseases including ischemia and reperfusion injury, and inflammatory diseases. The mechanisms underlying the protective effects of methane appear primarily to involve anti-oxidation, anti-inflammation, and anti-apoptosis. In this review, we describe the beneficial effects of methane on different diseases, summarize possible mechanisms by which methane may act in these conditions, and discuss the purpose of methane production in hypoxic conditions. Then we propose several promising directions for the future research.
Topics: Antioxidants; Apoptosis; Humans; Inflammation; Ischemia; Methane; Reperfusion Injury
PubMed: 32748575
DOI: 10.1631/jzus.B1900629 -
Mass Spectrometry Reviews Jul 2022This review is devoted to ion spectroscopy studies of complexes relevant for the understanding of methane activation with metal ions and clusters. Methane activation... (Review)
Review
This review is devoted to ion spectroscopy studies of complexes relevant for the understanding of methane activation with metal ions and clusters. Methane activation starts with the formation of a complex with a metal ion. The degree of the interaction between an intact methane molecule and the ion can be monitored by the perturbations of C-H stretch vibrations in the methane molecule. Binding mediated by the electrostatic interaction results in a η type coordination of methane. In contrast, binding governed by orbital interactions results in a η type coordination of methane. We further review the spectroscopic characterization of activation products of metal-methane reactions, such as the metal-carbene and carbyne products resulting from the interaction of selected 5d metals with methane. The focus of recent research in the field has shifted towards the investigation of interactions between methane and metal clusters. We show examples highlighting that metal clusters can be more reactive in methane activation reactions.
Topics: Ions; Mass Spectrometry; Metals; Methane; Spectrum Analysis
PubMed: 34008884
DOI: 10.1002/mas.21698 -
Annual Review of Microbiology Sep 2022Methane is one of the most important greenhouse gases on Earth and holds an important place in the global carbon cycle. Archaea are the only organisms that use... (Review)
Review
Methane is one of the most important greenhouse gases on Earth and holds an important place in the global carbon cycle. Archaea are the only organisms that use methanogenesis to produce energy and rely on the methyl-coenzyme M reductase complex (Mcr). Over the last decade, new results have significantly reshaped our view of the diversity of methane-related pathways in the Archaea. Many new lineages that synthesize or use methane have been identified across the whole archaeal tree, leading to a greatly expanded diversity of substrates and mechanisms. In this review, we present the state of the art of these advances and how they challenge established scenarios of the origin and evolution of methanogenesis, and we discuss the potential trajectories that may have led to this strikingly wide range of metabolisms.
Topics: Archaea; Methane; Oxidation-Reduction; Phylogeny
PubMed: 35759872
DOI: 10.1146/annurev-micro-041020-024935 -
Medical Gas Research 2023Methane has shown protective effects on a variety of diseases. Among these, neurological diseases have attracted much attention. However, there are many different... (Review)
Review
Methane has shown protective effects on a variety of diseases. Among these, neurological diseases have attracted much attention. However, there are many different indicators and application methods of methane in the treatment of neurological diseases. In this review, we summarize the indicators related to the protective effects of methane and evaluate the preparation and administration of methane. Thus, we hope to offer available indicators and effective ways to produce and administer methane in future research.
Topics: Methane; Nervous System Diseases; Humans
PubMed: 37077112
DOI: 10.4103/2045-9912.372663 -
Biological Chemistry Nov 2020Aerobic methane-oxidizing bacteria, or methanotrophs, play a crucial role in the global methane cycle. Their methane oxidation activity in various environmental settings... (Review)
Review
Aerobic methane-oxidizing bacteria, or methanotrophs, play a crucial role in the global methane cycle. Their methane oxidation activity in various environmental settings has a great mitigation effect on global climate change. Alphaproteobacterial methanotrophs were among the first to be taxonomically characterized, nowadays unified in the Methylocystaceae and Beijerinckiaceae families. Originally thought to have an obligate growth requirement for methane and related one-carbon compounds as a source of carbon and energy, it was later shown that various alphaproteobacterial methanotrophs are facultative, able to grow on multi-carbon compounds such as acetate. Most recently, we expanded our knowledge of the metabolic versatility of alphaproteobacterial methanotrophs. We showed that Methylocystis sp. strain SC2 has the capacity for mixotrophic growth on H2 and CH4. This mini-review will summarize the change in perception from the long-held paradigm of obligate methanotrophy to today's recognition of alphaproteobacterial methanotrophs as having both facultative and mixotrophic capabilities.
Topics: Alphaproteobacteria; Methane; Oxidation-Reduction
PubMed: 32769217
DOI: 10.1515/hsz-2020-0200 -
Proceedings of the National Academy of... Apr 2022Methane has been proposed as an exoplanet biosignature. Imminent observations with the James Webb Space Telescope may enable methane detections on potentially habitable...
Methane has been proposed as an exoplanet biosignature. Imminent observations with the James Webb Space Telescope may enable methane detections on potentially habitable exoplanets, so it is essential to assess in what planetary contexts methane is a compelling biosignature. Methane’s short photochemical lifetime in terrestrial planet atmospheres implies that abundant methane requires large replenishment fluxes. While methane can be produced by a variety of abiotic mechanisms such as outgassing, serpentinizing reactions, and impacts, we argue that—in contrast to an Earth-like biosphere—known abiotic processes cannot easily generate atmospheres rich in CH4 and CO2 with limited CO due to the strong redox disequilibrium between CH4 and CO2. Methane is thus more likely to be biogenic for planets with 1) a terrestrial bulk density, high mean-molecular-weight and anoxic atmosphere, and an old host star; 2) an abundance of CH4 that implies surface fluxes exceeding what could be supplied by abiotic processes; and 3) atmospheric CO2 with comparatively little CO.
Topics: Atmosphere; Earth, Planet; Exobiology; Extraterrestrial Environment; Methane; Planets
PubMed: 35353627
DOI: 10.1073/pnas.2117933119 -
Oxidative Medicine and Cellular... 2018Methane, the simplest organic compound, was deemed to have little physiological action for decades. However, recently, many basic studies have discovered that methane... (Review)
Review
Methane, the simplest organic compound, was deemed to have little physiological action for decades. However, recently, many basic studies have discovered that methane has several important biological effects that can protect cells and organs from inflammation, oxidant, and apoptosis. Heretofore, there are two delivery methods that have been applied to researches and have been proved to be feasible, including the inhalation of methane gas and injection with the methane-rich saline. This review studies on the clinical development of methane and discusses about the mechanism behind these protective effects. As a new field in gas medicine, this study also comes up with some problems and prospects on methane and further studies.
Topics: Anti-Inflammatory Agents; Antioxidants; Apoptosis; Humans; Methane
PubMed: 29743971
DOI: 10.1155/2018/1912746 -
Topics in Current Chemistry 2010The use of N-heterocyclic carbenes as catalysts for organic transformations has received increased attention in the past 10 years. A discussion of catalyst development... (Review)
Review
The use of N-heterocyclic carbenes as catalysts for organic transformations has received increased attention in the past 10 years. A discussion of catalyst development and nucleophilic characteristics precedes a description of recent advancements and new reactions using N-heterocyclic carbenes in catalysis.
Topics: Catalysis; Heterocyclic Compounds; Methane; Molecular Structure; Oxidation-Reduction; Stereoisomerism
PubMed: 21494949
DOI: 10.1007/978-3-642-02815-1_18 -
Biochemistry Dec 2019Methyl-coenzyme M reductase (MCR) catalyzes the methane-forming step in methanogenic archaea. The active enzyme harbors the nickel(I) hydrocorphin coenzyme F-430 as a... (Review)
Review
Methyl (Alkyl)-Coenzyme M Reductases: Nickel F-430-Containing Enzymes Involved in Anaerobic Methane Formation and in Anaerobic Oxidation of Methane or of Short Chain Alkanes.
Methyl-coenzyme M reductase (MCR) catalyzes the methane-forming step in methanogenic archaea. The active enzyme harbors the nickel(I) hydrocorphin coenzyme F-430 as a prosthetic group and catalyzes the reversible reduction of methyl-coenzyme M (CH-S-CoM) with coenzyme B (HS-CoM) to methane and CoM-S-S-CoB. MCR is also involved in anaerobic methane oxidation in reverse of methanogenesis and most probably in the anaerobic oxidation of ethane, propane, and butane. The challenging question is how the unreactive CH-S thioether bond in methyl-coenzyme M and the even more unreactive C-H bond in methane and the other hydrocarbons are anaerobically cleaved. A key to the answer is the negative redox potential (') of the Ni(II)F-430/Ni(I)F-430 couple below -600 mV and the radical nature of Ni(I)F-430. However, the negative one-electron redox potential is also the Achilles heel of MCR; it makes the nickel enzyme one of the most O-sensitive enzymes known to date. Even under physiological conditions, the Ni(I) in MCR is oxidized to the Ni(II) or Ni(III) states, e.g., when in the cells the redox potential (') of the CoM-S-S-CoB/HS-CoM and HS-CoB couple (' = -140 mV) gets too high. Methanogens therefore harbor an enzyme system for the reactivation of inactivated MCR in an ATP-dependent reduction reaction. Purification of active MCR in the Ni(I) oxidation state is very challenging and has been achieved in only a few laboratories. This perspective reviews the function, structure, and properties of MCR, what is known and not known about the catalytic mechanism, how the inactive enzyme is reactivated, and what remains to be discovered.
Topics: Anaerobiosis; Biocatalysis; Methane; Nickel; Oxidation-Reduction; Oxidoreductases
PubMed: 30951290
DOI: 10.1021/acs.biochem.9b00164 -
Proceedings of the National Academy of... Oct 2022China is set to actively reduce its methane emissions in the coming decade. A comprehensive evaluation of the current situation can provide a reference point for...
China is set to actively reduce its methane emissions in the coming decade. A comprehensive evaluation of the current situation can provide a reference point for tracking the country's future progress. Here, using satellite and surface observations, we quantify China's methane emissions during 2010-2017. Including newly available data from a surface network across China greatly improves our ability to constrain emissions at subnational and sectoral levels. Our results show that recent changes in China's methane emissions are linked to energy, agricultural, and environmental policies. We find contrasting methane emission trends in different regions attributed to coal mining, reflecting region-dependent responses to China's energy policy of closing small coal mines (decreases in Southwest) and consolidating large coal mines (increases in North). Coordinated production of coalbed methane and coal in southern Shanxi effectively decreases methane emissions, despite increased coal production there. We also detect unexpected increases from rice cultivation over East and Central China, which is contributed by enhanced rates of crop-residue application, a factor not accounted for in current inventories. Our work identifies policy drivers of recent changes in China's methane emissions, providing input to formulating methane policy toward its climate goal.
Topics: Agriculture; China; Coal; Methane; Policy
PubMed: 36191196
DOI: 10.1073/pnas.2202742119