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The Science of the Total Environment Jun 2024In the context of the increasing global use of ethanol biofuel, this work investigates the concentrations of ethanol, methanol, and acetaldehyde, in both the gaseous...
In the context of the increasing global use of ethanol biofuel, this work investigates the concentrations of ethanol, methanol, and acetaldehyde, in both the gaseous phase and rainwater, across six diverse urban regions and biomes in Brazil, a country where ethanol accounts for nearly half the light-duty vehicular fuel consumption. Atmospheric ethanol median concentrations in São Paulo (SP) (12.3 ± 12.1 ppbv) and Ribeirão Preto (RP) (12.1 ± 10.9 ppbv) were remarkably close, despite the SP vehicular fleet being ∼13 times larger. Likewise, the rainwater VWM ethanol concentration in SP (4.64 ± 0.38 μmol L) was only 26 % higher than in RP (3.42 ± 0.13 μmol L). This work demonstrated the importance of evaporative emissions, together with biomass burning, as sources of the compounds studied. The importance of biogenic emissions of methanol during forest flooding was identified in campaigns in the Amazon and Atlantic forests. Marine air masses arriving at a coastal site led to the lowest concentrations of ethanol measured in this work. Besides vehicular and biomass burning emissions, secondary formation of acetaldehyde by photochemical reactions may be relevant in urban and non-urban regions. The combined deposition flux of ethanol and methanol was 6.2 kg ha year, avoiding oxidation to the corresponding and more toxic aldehydes. Considering the species determined here, the ozone formation potential (OFP) in RP was around two-fold higher than in SP, further evidencing the importance of emissions from regional distilleries and biomass burning, in addition to vehicles. At the forest and coastal sites, the OFP was approximately 5 times lower than at the urban sites. Our work evidenced that transition from gasoline to ethanol or ethanol blends brings the associated risk of increasing the concentrations of highly toxic aldehydes and ozone, potentially impacting the atmosphere and threatening air quality and human health in urban areas.
Topics: Brazil; Acetaldehyde; Ethanol; Environmental Monitoring; Methanol; Rain; Air Pollutants; Cities
PubMed: 38649057
DOI: 10.1016/j.scitotenv.2024.172629 -
Journal of the American Society For... Apr 2020Gas phase modification in ESI-MS can significantly alter the charge state distribution of small peptides and proteins. The preceding paper presented a systematic...
Gas phase modification in ESI-MS can significantly alter the charge state distribution of small peptides and proteins. The preceding paper presented a systematic experimental study on this topic using Substance P and proposed a charge retention/charge depletion mechanism, explaining different gas- and liquid-phase modifications [Thinius et al. 2020, 10.1021/jasms.9b00044]. In this work, we aim to support this rational by theoretical investigations on the proton transfer processes from (multiply) charged analytes toward solvent clusters. As model systems we use small (di)amines as analytes and methanol (MeOH) and acetonitrile (ACN) as gas phase modifiers. The calculations are supported by a set of experiments using (di)amines, to bridge the gap between the present model system and Substance P used in the preceding study. Upon calculation of the thermochemical stability as well as the proton transfer pathways, we find that both ACN and MeOH form stable adduct clusters at the protonation site. MeOH can form large clusters through a chain of H-bridges, eventually lowering the barriers for proton transfer to an extent that charge transfer from the analyte to the MeOH cluster becomes feasible. ACN, however, cannot form H-bridged structures due to its aprotic nature. Hence, the charge is retained at the original protonation site, i.e., the analyte. The investigation confirms the proposed charge retention/charge depletion model. Thus, adding aprotic solvent vapors to the gas phase of an ESI source more likely yields higher charge states than using protic compounds.
Topics: Acetonitriles; Diamines; Gases; Lysine; Methanol; Models, Chemical; Protons; Spectrometry, Mass, Electrospray Ionization
PubMed: 32150409
DOI: 10.1021/jasms.9b00045 -
Parasites & Vectors Jul 2023Helminth infections are an important public health problem in humans and have an even greater impact on domestic animal and livestock welfare. Current readouts for...
BACKGROUND
Helminth infections are an important public health problem in humans and have an even greater impact on domestic animal and livestock welfare. Current readouts for anthelmintic drug screening assays are stage development, migration, or motility that can be subjective, laborious, and low in throughput. The aim of this study was to apply and optimize a fluorometric technique using resazurin for evaluating changes in the metabolic activity of Ascaris suum third-stage larvae (L3), a parasite of high economic relevance in swine.
METHODS
Ascaris suum L3 were mechanically hatched from 6- to 8-week embryonated and sucrose-gradient-enriched eggs. Resazurin dye and A. suum L3 were titrated in 96-well microtiter plates, and resazurin reduction activity was assessed by fluorometry after 24 h of incubation. Fluorescence microscopy was used to localize the resazurin reduction site within the larvae. Finally, we exposed A. suum L3 to various stress conditions including heat, methanol, and anthelmintics, and investigated their impact on larval metabolism through resazurin reduction activity.
RESULTS
We show that the non-fluorescent dye resazurin is reduced inside vital A. suum L3 to fluorescent resorufin and released into the culture media. Optimal assay parameters are 100-1000 L3 per well, a resazurin concentration of 7.5 µg/ml, and incubation at 37 °C/5% CO for 24 h. An intact L2 sheath around the L3 of A. suum completely prevents the uptake of resazurin, while in unsheathed L3, the most intense fluorescence signal is observed along the larval midgut. L3 exposed to methanol or heat show a gradually decreased resazurin reduction activity. In addition, 24 h exposure to ivermectin at 0.625 µM, mebendazole at 5 µM, and thiabendazole from 10 to 100 µM significantly decreased larval metabolic activity by 55%, 73%, and 70% to 89%, respectively.
CONCLUSIONS
Together, our results show that both metabolic stressors and anthelmintic drugs significantly and reproducibly reduce the resazurin reduction activity of A. suum L3, making the proposed assay a sensitive and easy-to-use method to evaluate metabolic activity of A. suum L3 in vitro.
Topics: Humans; Animals; Swine; Ascaris suum; Methanol; Anthelmintics; Xanthenes; Ascariasis; Larva
PubMed: 37468906
DOI: 10.1186/s13071-023-05871-5 -
Proceedings of the National Academy of... Mar 2023Methanol is an ideal feedstock for chemical and biological manufacturing. Constructing an efficient cell factory is essential for producing complex compounds through...
Methanol is an ideal feedstock for chemical and biological manufacturing. Constructing an efficient cell factory is essential for producing complex compounds through methanol biotransformation, in which coordinating methanol use and product synthesis is often necessary. In methylotrophic yeast, methanol utilization mainly occurs in peroxisomes, which creates challenges in driving the metabolic flux toward product biosynthesis. Here, we observed that constructing the cytosolic biosynthesis pathway resulted in compromised fatty alcohol production in the methylotrophic yeast . Alternatively, peroxisomal coupling of fatty alcohol biosynthesis and methanol utilization significantly improved fatty alcohol production by 3.9-fold. Enhancing the supply of precursor fatty acyl-CoA and cofactor NADPH in the peroxisomes by global metabolic rewiring further improved fatty alcohol production by 2.5-fold and produced 3.6 g/L fatty alcohols from methanol under fed-batch fermentation. We demonstrated that peroxisome compartmentalization is helpful for coupling methanol utilization and product synthesis, and with this approach, constructing efficient microbial cell factories for methanol biotransformation is feasible.
Topics: Fatty Alcohols; Methanol; Peroxisomes; Fermentation; Metabolic Engineering
PubMed: 36913588
DOI: 10.1073/pnas.2220816120 -
Biomedicine & Pharmacotherapy =... Jul 2020Chagas disease, caused by the protozoan parasiteTrypanosoma cruzi, has no effective treatment available. On the other hand, microalgae are aquatic organisms that...
INTRODUCTION
Chagas disease, caused by the protozoan parasiteTrypanosoma cruzi, has no effective treatment available. On the other hand, microalgae are aquatic organisms that constitute an interesting reservoir of biologically active metabolites. Moreover, some species of green and red algae present anti-protozoan activity. Our aim was to study the antiparasitic effects of aqueous, methanolic and ethanolic extracts from different microalgae.
METHODS AND RESULTS
Our results show that the methanolic extracts of S. obliquus and T. suecica as well as the ethanolic extracts of C. reinhardtii and T. suecica present trypanocidal activity on the infective extracellular trypomastigotes and intracellular amastigotes. In addition, the ethanolic extract of C. reinhardtii potentiates the activity of the conventional antichagasic drug nifurtimox. In order to identify some potential compounds with trypanocidal activity, we performed a phytochemical screening analyzing the presence of phenolic compounds, pigments and terpenoids.
CONCLUSION
The different microalgae extracts, particularly the ethanolic extract ofC. reinhardtii, are promising potential candidates for the development of future natural antichagasic drugs.
Topics: Animals; Chagas Disease; Chlorocebus aethiops; Ethanol; Methanol; Microalgae; Trypanocidal Agents; Trypanosoma cruzi; Vero Cells
PubMed: 32371317
DOI: 10.1016/j.biopha.2020.110178 -
Molecules (Basel, Switzerland) Apr 2023The purpose of this work was to investigate, for the first time to our knowledge, the chemical composition and bioactivity of methanolic extracts (roots, stems, leaves,...
The purpose of this work was to investigate, for the first time to our knowledge, the chemical composition and bioactivity of methanolic extracts (roots, stems, leaves, and flowers) from (L.) Chevall. that grows wild in northern Morocco (the Tangier-Tetouan-Al Hoceima region). The phenolic and flavonoid contents were determined by spectrophotometer methods, and the composition of derivatized methanolic extracts from using --bis(trimethylsilyl) trifluoroacetamide (BSTFA) was analyzed by gas chromatography-mass spectrometry (GC-MS). The antioxidant activity was carried out by applying the 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and DPPH (2,2-diphenyl-1-picrylhydrazyl) tests. The micro-dilution technique was chosen to investigate the antimicrobial activity of methanolic extracts against two bacterial strains and three fungal species. The results showed that the values of total phenolic and flavonoid contents were found to be higher in flower extracts (30.55 ± 0.85 mg of gallic acid equivalents (GAE)/g of dried weight (DW) and 26.00 ±1.34 mg of quercetin equivalents (QE)/g DW, respectively). Other groups of chemical compounds were revealed by GC-MS, such as carbohydrates (27.25-64.87%), fatty acids (1.58-9.08%), organic acids (11.81-18.82%), and amino acids (1.26-7.10%). Root and flower methanolic extracts showed the highest antioxidant activity using ABTS (39.49 mg of Trolox equivalents (TE)/g DW) and DPPH (36.23 mg TE/g DW), respectively. A positive correlation between antioxidant activity and polyphenol and flavonoid amounts was found. Antibacterial tests showed that the best activity was presented by the leaf extract against (minimum inhibitory concentration (MIC) = minimum bactericidal concentration (MBC) = 20 mg/mL) and (MIC of 30 mg/mL and MBC of 35 mg/mL). was more sensitive to the extracts compared to . All extracts showed antifungal activity against , with the best efficacy reported by the flower and leaf extracts (MIC = 1.25 mg/mL and minimum fungicidal concentration (MFC) = 2.5 mg/mL). In general, extracts of appeared less effective against and .
Topics: Plant Extracts; Antioxidants; Staphylococcus aureus; Escherichia coli; Morocco; Flavonoids; Phenols; Methanol
PubMed: 37049958
DOI: 10.3390/molecules28073196 -
Marine Pollution Bulletin May 2023Historical exposure of the marine environment to 2,4,6-trinitrotoluene (TNT) happened due to the dumping of left-over munitions. Despite significant research on TNT...
Historical exposure of the marine environment to 2,4,6-trinitrotoluene (TNT) happened due to the dumping of left-over munitions. Despite significant research on TNT decontamination, the potential of marine microbiome for TNT degradation remains only little explored. In this study, TNT degradation experiments were conducted with sediment located near the World War I munition dumpsite - Paardenmarkt in the Belgian part of North Sea. A slow removal was observed using TNT as sole source of C and N, which could be enhanced by adding methanol. Degradation was reflected in nitro-reduced metabolites and microbial growth. 16S Illumina sequencing analysis revealed several enriched genera that used TNT as a sole source of C and N - Colwellia, Thalossospira, and Methylophaga. Addition of methanol resulted in increased abundance of Methylophaga, which corresponded to the rapid removal of TNT. Methanol enhanced the degradation by providing additional energy and establishing syntrophic association between methanol-utilizing and TNT-utilizing bacteria.
Topics: Methanol; Trinitrotoluene; Bacteria; North Sea
PubMed: 37001405
DOI: 10.1016/j.marpolbul.2023.114866 -
Analytical Chemistry Mar 2022The effect of makeup solvent composition in ultrahigh-performance supercritical fluid chromatography-triple quadrupole mass spectrometry using electrospray ionization...
The effect of makeup solvent composition in ultrahigh-performance supercritical fluid chromatography-triple quadrupole mass spectrometry using electrospray ionization was studied using a set of 91 compounds, 3 stationary phases, and 2 organic modifiers of the mobile phase. The 24 tested makeup solvents included pure alcohols and methanol in combination with commonly used additives such as water, formic and acetic acid, ammonia, and ammonia salts with varying molarity. The behavioral trends for different makeup solvent additives were established in the first step. Subsequently, the correlations between physicochemical properties and the MS responses were calculated using the Pearson correlation test and matrix plots. The regression analysis was performed using five descriptors: molecular weight, p, log , number of hydrogen donors/acceptors, and the MS responses obtained with methanol as the makeup solvent. The resulting regression equations had a high prediction rate calculated as -predicted coefficient, especially when 10 mmol/L ammonium in methanol was used as an organic modifier of the mobile phase in positive mode. The trueness of these equations was tested via the comparison between experimental and predicted responses expressed as . Values of > 0.8 were found for 88% of the proposed equations. Thus, the MS response could be measured using only one makeup solvent and the responses of other makeup solvents could be easily estimated. The suitability and applicability of determined regression equations was confirmed by the analysis of 13 blind probes, i.e., compounds not included in the original set of analytes. Moreover, the predicted and experimental responses followed the same increasing/decreasing trend enabling one to predict makeup solvent compositions leading to the highest sensitivity.
Topics: Acetic Acid; Ammonia; Chromatography, Supercritical Fluid; Mass Spectrometry; Methanol; Solvents
PubMed: 35274936
DOI: 10.1021/acs.analchem.2c00154 -
Veterinary Medicine and Science Jul 2023Plants are widely used in traditional medicine because they contain a high concentration of antimicrobial agents, serving as the foundation for medicines. The aim of...
INTRODUCTION
Plants are widely used in traditional medicine because they contain a high concentration of antimicrobial agents, serving as the foundation for medicines. The aim of this study was preliminary identification of phytochemicals and assesses the antimicrobial activity of extracts of Ferula communis root bark.
METHODS
Plant was collected, and standard qualitative procedures were conducted. The plant samples were extracted with 99.9% methanol and 80% ethanol. To identify phytochemicals found in plants, a preliminary phytochemical analysis was performed. Agar diffusion tests, minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were performed to evaluate antibacterial activity.
RESULT
The preliminary phytochemical analysis of the ethanol and methanol extract revealed positive results for flavonoids, coumarins and tannins. Terpenoids and anthraquinones were detected only in the methanol extract. The extract of Ferula communis showed an antibacterial effect on both gram-negative and gram-positive bacteria in a concentration-dependent manner. The average zone of inhibition for gram-positive bacteria was 11 mm, whereas for gram-negative bacteria, it was 9 mm. The MIC and MBC values also varied with the type of bacteria. In all bacterial species tested, the mean MBC value was similar to the MIC.
CONCLUSION
Different phytochemicals were detected in extracts of the root bark of F. communis and extracts showed antibacterial effects in a concentration-dependent manner. Therefore, further purification and evaluation of the extracts and antioxidant activity of the plant should be investigated.
Topics: Animals; Plant Extracts; Ferula; Apiaceae; Methanol; Plant Bark; Anti-Bacterial Agents; Phytochemicals; Bacteria; Gram-Positive Bacteria; Ethanol
PubMed: 37392454
DOI: 10.1002/vms3.1170 -
Bioresource Technology Mar 2022Exploiting highly active and methanol-resistant lipase is of great significance for biodiesel production. A semi-rational directed evolution method combined with...
Exploiting highly active and methanol-resistant lipase is of great significance for biodiesel production. A semi-rational directed evolution method combined with N-glycosylation is reported, and all mutants exhibiting higher catalytic activity and methanol tolerance than the wild type (WT). Mutant N267 retained 64% activity after incubation in 50% methanol for 8 h, which was 48% greater than that of WT. The catalytic activity of mutants N267 and N167 was 30- and 71- fold higher than that of WT. Molecular dynamics simulations of N267 showed that the formation of new strong hydrogen bonds between glycan and the protein stabilized the structure of lipase and improved its methanol tolerance. N267 achieved biodiesel yields of 99.33% (colza oil) and 81.70% (waste soybean oil) for 24 h, which was much higher than WT (51.6% for rapeseed oil and 44.73% for wasted soybean oil). The engineered ProRML mutant has high potential for commercial biodiesel production.
Topics: Biofuels; Lipase; Methanol; Rhizomucor
PubMed: 35092821
DOI: 10.1016/j.biortech.2022.126769