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Chemical Senses Jan 2024Although studies have shown that olfaction may contribute to the perception of tastant, literature is scarce or circumstantial, especially in humans. This study aims to...
Although studies have shown that olfaction may contribute to the perception of tastant, literature is scarce or circumstantial, especially in humans. This study aims to (i) explore whether humans can perceive solutions of basic prototypical tastants through orthonasal and retronasal olfaction and (ii) to examine what volatile odor compounds (VOCs) underlie this ability. Solutions of 5 basic tastants (sucrose, sodium chloride, citric acid, monosodium glutamate [MSG], quinine) dissolved in water, and 2 fatty acids (oleic and linoleic acid) dissolved in mineral oil were prepared. Triangle discrimination tests were performed (n = 41 in duplicate) to assess whether the tastant solutions can be distinguished from blanks (solvents) through ortho- and retronasal olfaction. Participants were able to distinguish all tastant solutions from blank through orthonasal olfaction. Only sucrose, sodium chloride, oleic acid, and linoleic acid were distinguished from blank by retronasal olfaction. Ethyl dichloroacetate, methylene chloride, and/or acetone were identified in the headspace of sucrose, MSG, and quinine solutions but not in the headspace of water, sodium chloride, and citric acid solutions. Fat oxidation compounds such as alcohols and aldehydes were detected in the headspace of the oleic and linoleic acid solutions but not the mineral oil. We conclude that prototypical tastant solutions can be discriminated from water and fatty acid solutions from mineral oil through orthonasal olfaction. Differences in the volatile headspace composition between blanks and tastant solutions may have facilitated the olfactory discrimination. These findings can have methodological implications for future studies assessing gustatory perception using these prototypical taste compounds.
Topics: Humans; Smell; Sodium Chloride; Sodium Glutamate; Quinine; Mineral Oil; Taste; Water; Sucrose; Citric Acid; Linoleic Acids
PubMed: 38175732
DOI: 10.1093/chemse/bjad054 -
Drug Discoveries & Therapeutics Jul 2023The use of harmful solvents during the preparation of pharmaceutical formulations is restricted to preserve environment and ensure safety of industrial operations.... (Review)
Review
The use of harmful solvents during the preparation of pharmaceutical formulations is restricted to preserve environment and ensure safety of industrial operations. However, harmful solvents must be used to produce certain formulations. For instance, methylene chloride has been used in the fabrication of polylactic acid (PLA) and poly(lactic-co-glycolic) acid (PLGA) microspheres. This review highlights the latest advances in the strategy of PLA or PLGA microsphere production from non-halogenated solvents and describes advantages and limitations of these methods. The study also discusses the development of dry fabrication techniques for microsphere fabrication and the positioning of conventional and dry fabrication in the containment concept for workers' safety.
Topics: Humans; Polylactic Acid-Polyglycolic Acid Copolymer; Polyglycolic Acid; Lactic Acid; Microspheres; Polyesters; Solvents; Particle Size
PubMed: 37245983
DOI: 10.5582/ddt.2023.01008 -
Molecules (Basel, Switzerland) Oct 2023The recent rapid growth of the battery industry has led to a rapid increase in methylene chloride emissions. Methylene chloride causes health and social problems in...
The recent rapid growth of the battery industry has led to a rapid increase in methylene chloride emissions. Methylene chloride causes health and social problems in humans. In this study, cellulose-based activated carbon fibers (CACFs) with improved yield were prepared for the removal of methylene chloride. The concentration of ammonium phosphate in the pretreatment controlled the crosslink density of cellulose fibers and improved the yield. From the results, the specific surface area and total pore volume of cellulose-based activated carbon fibers pretreated with ammonium phosphate (AP-CACFs) were determined to be 1920-2060 m/g and 0.83-1.02 cm/g, respectively, and the total yield improved by 6.78-11.59% compared to that of CACFs (4.97%). In particular, a correlation between the textural properties of CACFs and methylene chloride adsorption/desorption behavior was obtained. This correlation can be used to develop efficient adsorbents for methylene chloride removal.
PubMed: 37836838
DOI: 10.3390/molecules28196997 -
The Science of the Total Environment Jun 2024Parkinson's disease (PD) is a neurodegenerative disorder and leading cause of death worldwide, whose pathogenesis has been linked to toxic environmental exposures. We... (Meta-Analysis)
Meta-Analysis Review
Parkinson's disease (PD) is a neurodegenerative disorder and leading cause of death worldwide, whose pathogenesis has been linked to toxic environmental exposures. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (i) to compile, and group by exposure setting (non-specified general; residential; occupational), environmental factors reported to modulate the risk of developing PD and (ii) to map and geospatially analyze global regions of both research activity and paucity. Among the broader environmental settings, occupational exposures had the highest average odds ratio value at 3.82, followed by general (non-specified or mixed) exposures at 3.07, and residential exposures at 2.36. Occupational exposure to industrial toxins was the highest ranked subset of exposures with an odds ratio of 10.74. Among the studies meeting the inclusion criteria, 75 % were conducted in Europe or the Western United States. The number of individuals partaking per study ranged from a high of 55,585 (Taiwan) to a low of 233 (Faroe Islands), with a mean of n = 14,462. The top three environmental factors associated with high odds ratios for increased risk of developing PD were (i) exposure to dyes (25.33), (ii) methylene chloride (16.5) and specifically in adult men (iii) consumption of fatty whale meat (10.57), which is known to harbor a broad spectrum of so called persistent, bioaccumulative, toxic (PBT) pollutants. Geospatially, the highest odds ratio values were identified in European countries, whereas notable data gaps were revealed for South America, Australia, Africa, and the majority of Asia with the exception of Taiwan. Whereas occupational exposures to industrial chemicals, such as harmful dyes and methylene chloride, ranked highest in risk values, available data suggest notable opportunities for reducing PD cases globally by limiting harmful environmental exposures to a spectrum of toxic chemicals, particularly via the food intake route. Thus, current efforts in improving environmental quality globally by limiting toxic emission may deliver the added benefit of helping to reign in PD. Agents of concern in this respect include pesticides (e.g., paraquat, demeton, monocrotophos), particulate matter associated with air pollution, and a spectrum of organic and inorganic neurotoxins including heavy metals.
Topics: Parkinson Disease; Humans; Environmental Exposure; Environmental Pollutants; Risk Factors; Occupational Exposure
PubMed: 38685425
DOI: 10.1016/j.scitotenv.2024.172838 -
Proceedings of the National Academy of... Mar 2024The cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel that regulates electrolyte and fluid balance in epithelial tissues. While activation...
The cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel that regulates electrolyte and fluid balance in epithelial tissues. While activation of CFTR is vital to treating cystic fibrosis, selective inhibition of CFTR is a potential therapeutic strategy for secretory diarrhea and autosomal dominant polycystic kidney disease. Although several CFTR inhibitors have been developed by high-throughput screening, their modes of action remain elusive. In this study, we determined the structure of CFTR in complex with the inhibitor CFTR-172 to an overall resolution of 2.7 Å by cryogenic electron microscopy. We observe that CFTR-172 binds inside the pore near transmembrane helix 8, a critical structural element that links adenosine triphosphate hydrolysis with channel gating. Binding of CFTR-172 stabilizes a conformation in which the chloride selectivity filter is collapsed, and the pore is blocked from the extracellular side of the membrane. Single-molecule fluorescence resonance energy transfer experiments indicate that CFTR-172 inhibits channel gating without compromising nucleotide-binding domain dimerization. Together, these data reconcile previous biophysical observations and provide a molecular basis for the activity of this widely used CFTR inhibitor.
Topics: Cystic Fibrosis Transmembrane Conductance Regulator; Dimerization; Adenosine Triphosphate; Benzoates; Thiazolidines
PubMed: 38422021
DOI: 10.1073/pnas.2316675121 -
Biomedicine & Pharmacotherapy =... Nov 2023Clivia miniata (Lindl) is a member of the family Amaryllidaceae known for its chemically diverse alkaloids with a wide range of biological activities. Many reports...
Clivia miniata (Lindl) is a member of the family Amaryllidaceae known for its chemically diverse alkaloids with a wide range of biological activities. Many reports revealed a direct role of oxidative stress in the early stage of Alzheimer's disease (AD). Meanwhile, β-site amyloid precursor protein cleavage enzyme 1 (BACE-1) is a molecular target for the treatment of AD. We aimed to investigate C. miniata root, bulb, and aerial part chemical profiling, antioxidant, BACE-1, and AChE enzyme inhibitory activities. Results showed that the total root had the most potent radical scavenging activity as compared to the total bulb and aerial part, respectively. Ethanol root extract had the most potent BACE-1 inhibitory activity (IC = 0.02 ± 0.001 µg/mL) as compared to the bulb and aerial part (IC = 0.93 ± 0.13, 1.80 ± 0.24 µg/mL), respectively. Moreover, the total root extract mitigated AChE enzyme activity more than total bulb and aerial fractions with IC values of (0.06 ± 0.02, 0.58 ± 0.3, and 1.89 ± 0.42 µg/mL, respectively. Bioassay-guided acid-base fractionation confirmed superior BACE-1 inhibitory activity of the root fractions particularly, methylene chloride and ethyl acetate fractions with (IC values of 0.21 ± 0.60 and 0.01 ± 0.001 µg/mL), respectively. UPLC-MS analysis of ethyl acetate and methylene chloride fractions of C. miniata root led to the identification of eight phenolics and thirteen alkaloids, respectively. Molecular docking studies against BACE-1 protein revealed that lycorine di-hexoside, miniatine, and cliviaaline were the most promising hits. Further investigation of anti-AD potential of the aforementioned small molecules is required.
Topics: Antioxidants; Molecular Docking Simulation; Chromatography, Liquid; Methylene Chloride; Tandem Mass Spectrometry; Alkaloids; Plant Extracts; Alzheimer Disease; Plant Components, Aerial; Amaryllidaceae; Cholinesterase Inhibitors
PubMed: 37778271
DOI: 10.1016/j.biopha.2023.115382 -
Cureus Aug 2023Calcium channel blocker poisoning is one of the most common poisonings encountered which presents with life-threatening complications. However, there is no unified... (Review)
Review
Calcium channel blocker poisoning is one of the most common poisonings encountered which presents with life-threatening complications. However, there is no unified approach for treating these patients in the existing literature. This study aimed to assess the effects of different treatment modalities used in calcium channel blocker poisoning, as reported by previous studies. The primary outcomes studied were mortality and hemodynamic parameters after treatment. The secondary outcomes were the length of hospital stay, length of intensive care unit stay, duration of vasopressor use, functional outcomes, and serum calcium channel blocker concentrations. A thorough literature search was performed through Ovid, PubMed, Cochrane Library, and Google Scholar from January 2014 to December 31, 2022, to identify all studies analyzing the effects of the treatment of calcium channel blocker poisoning on the desired outcomes. Two reviewers reviewed 607 published articles from January 2014 to December 2022 to identify studies analyzing the effects of the treatment of calcium channel blocker poisoning on desired outcomes. In this review, 18 case reports, one case series, and one cohort study were included. Most patients were treated with an injection of calcium gluconate or calcium chloride. The use of calcium along with dopamine and norepinephrine was found to have lower mortality rates. A few patients were also treated with injection atropine for bradycardia. High-dose insulin therapy was used in 14 patients, of whom two did not survive. In the cohort study, 66 calcium channel blocker toxicity patients were included. These patients were treated with high-dose insulin therapy. A total of 11 patients with calcium channel blocker toxicity succumbed. Although it was found to be associated with improved hemodynamic parameters and lower mortality, side effects such as hypokalemia and hypoglycemia were noted. Intravenous lipid emulsion therapy (administered to eight patients), extracorporeal life support (used in three patients with refractory shock or cardiac arrest), injection glucagon, methylene blue, albumin infusion, and terlipressin were associated with a lower mortality rate as well as improvement in hemodynamic parameters. None of the case reports provided any information on end-organ damage on long-term follow-up.
PubMed: 37664357
DOI: 10.7759/cureus.42854 -
ACS Omega Oct 2023Eutectic solvent systems are versatile solvents that have found widespread use in numerous applications. Traditional solvents are homogeneous, having only one component,...
Eutectic solvent systems are versatile solvents that have found widespread use in numerous applications. Traditional solvents are homogeneous, having only one component, and their chemistry is relatively simple, with some exceptions. On the other hand, deep eutectic solvents (DESs) comprise binary components, generally a donor and an acceptor in hydrogen bonding with varying ratios. The interaction chemistry among the donor and acceptor involved in hydrogen bonding in DESs is complicated. Although numerous research is focused on the synthesis and application of DESs, few studies are reported to elucidate the complex structure and dynamic and interaction behavior of DESs. In this study, we employed calorimetry, vibrational spectroscopy techniques including FTIR and Raman, and nuclear magnetic resonance to derive insight into the structural feature and noncovalent contact of choline chloride (ChCl) and citric acid (CA) while they formed DESs. The 1:1 ChCl/CA eutectic system showed phase transitions and melting peaks with the most pronounced peak at 156.22 °C, suggesting the DESs melting at a lower temperature than the melting temperatures of ChCl and CA. In addition to IR and Raman findings, H NMR investigations demonstrate hydrogen bonding intermolecular interactions between ChCl and CA, supporting the formation of 1:1 ChCl/CA DESs based on the deshielded chemical shifts of the proton for Ch. The interaction of the chloride anion with the methyl protons (H4) and methylene protons (H3) of ChCl as well as the strong hydrogen bonding interactions between the hydroxyl hydrogen (H1) of ChCl with one of CA's carbonyl oxygens both supported the formation of conformer E. In addition, molecular dynamics followed by the density functional theory (DFT) was employed to visualize the structure and interaction of DESs using the ωB97XD theory and 6-311++G (d,p) basis set. Both experimental and theoretical IR, Raman, and structural analyses provided evidence of the formation of DESs by possessing hydrogen bonds. These multifaceted experimental and computational investigations provide details of structural and intermolecular interactions of ChCl/CA DESs.
PubMed: 37867676
DOI: 10.1021/acsomega.3c04570 -
Iranian Journal of Basic Medical... 2024The newest virus from the SARS family of viruses called acute syndrome-coronavirus-2 (SARS-CoV-2), which causes COVID-19 disease, was identified in China at the end of... (Review)
Review
The newest virus from the SARS family of viruses called acute syndrome-coronavirus-2 (SARS-CoV-2), which causes COVID-19 disease, was identified in China at the end of 2019. In March 2020, after it spread to 29 additional countries, it was declared a pandemic by the World Health Organization (WHO). SARS-CoV-2 infection mainly starts through the respiratory tract and causes a wide spectrum of symptoms from asymptomatic infections to acute respiratory distress syndrome with multi-organ failure and vasoplegic shock. Among the many immunomodulatory and antiviral drugs that have been studied for the treatment of COVID-19, methylene blue (MB) may play an influential role. This article reviews the history of MB applications, the antiviral effects of MB against SARS-CoV-2, and the results of and studies of the use of MB in COVID-19. Based on studies, MB can simultaneously affect most of the host's harmful responses caused by SARS-CoV-2 infection due to its multiple properties, including anti-hypoxemia, anti-oxidant, immune system modulator, and antiviral. The use of MB is associated with a reduction in the possibility of getting infection, and mortality, and can be used as a safe, effective, cheap, and available treatment option with minimal side effects for the clinical management of COVID-19.
PubMed: 38800024
DOI: 10.22038/IJBMS.2024.71871.15617