Dimethylsulfide (CH(3)SCH(3)) is formed in anoxic freshwater sediments by biological methylation of methanethiol (CH(3)SH). We measured thiol methylation potential in low-pH, Sphagnum peat sediments from Alaska and Alabama by adding ethanethiol (CH(3)CH(2)SH) to peat slurries and quantifying the rate of ethylmethylsulfide (CH(3)CH(2)SCH(3)) formation. Thiol methylation potential ranged from 12 to 154 nM h(-1) and was significantly related to dimethylsulfide accumulation rates (P=0.0007; r(2)=0.48). Addition of methanol or syringic acid stimulated thiol methylation potential and dimethylsulfide accumulation rate, suggesting that these compounds could be methyl donors. Addition of acetate or its metabolic precursors (glucose or Sphagnum plant material) inhibited thiol methylation potential, but not carbon dioxide or methane production. Inhibition of methanogenesis with either 2-bromoethanesulfonic acid or KNO(3) consistently inhibited thiol methylation potential and dimethylsulfide accumulation. These results suggest that methanogens play a role in thiol methylation and therefore dimethylsulfide formation.
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http://dx.doi.org/10.1016/S0168-6496(03)00219-8 | DOI Listing |
Sheng Wu Gong Cheng Xue Bao
January 2025
Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, College of Bioengineering, Tianjin University of Science & Technology, Tianjin 300457, China.
-methyl-L-cysteine sulfoxide (SMCO) is a non-protein sulfur-containing amino acid with a variety of functions. There are few reports on the enzymes catalyzing the biosynthesis of SMCO from -methyl-L-cysteine (SMC). In this study, the flavin-containing monooxygenase gene derived from () was heterologously expressed in BL21(DE3) and the enzymatic properties of the expressed protein were analyzed.
View Article and Find Full Text PDFIran J Basic Med Sci
January 2025
Neuroscience Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
Objectives: Traumatic brain injury (TBI) is a significant cause of mortality and disability worldwide. TBI has been associated with factors such as oxidative stress, neuroinflammation, and apoptosis, which are believed to be mediated by the N-methyl-D-aspartate (NMDA)-type glutamate receptor. Two NMDA receptor antagonists, ketamine and memantine, have shown potential in mitigating the pathophysiological effects of TBI.
View Article and Find Full Text PDFChem Sci
January 2025
School of Chemical Engineering and Technology, GBRCE for Functional Molecular Engineering, IGCME, Sun Yat-sen University 519082 Zhuhai China.
Traditional photosensitive polyimide (PSPI) materials require a high curing temperature and exhibit low transparency, limiting their applications in thermally sensitive optical devices. To overcome this challenge, soluble photosensitive polyimide resins were synthesized based on the structural design of a bio-based magnolol monomer. It is noteworthy that the PI photoresist, developed by using the as-prepared polyimides and non-toxic solvents (2-acetoxy-1-methoxypropane, PGEMA) and other additives, demonstrated an impressive low-temperature curing performance (180 °C).
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Material Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois, 60439, United States.
Exposure of soft material templates to alternating volatile chemical precursors can produce inorganic deposition within the permeable template (e.g. a polymer thin film) in a process akin to atomic layer deposition (ALD).
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata, WB 700032, India.
Molecular catalysts with a single metal center are reported to reduce CO to a wide range of valuable single-carbon products like CO, HCOOH, CHOH, etc. However, these catalysts cannot reduce CO to two carbon products like ethane or ethylene and the ability to form C-C from CO remains mostly limited to heterogeneous material-based catalysts. We report a set of simple iron porphyrins with pendant thiol group can catalyze the reduction of CO to ethane (CH) with HO as the proton source with a Faradaic yield >40% the rest being CO.
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