Barbiturates And Minor Tranquilizers
S.J. Mulé, Henry Brill in Chemical and Biological Aspects of Drug Dependence, 2019
The 2-disubstituted propanediol precursor which is needed for the formation of meprobamate was synthesized by Ludwig and Piech.42 As shown in Figure 5, the precursor was made by a condensation of 2-methyl-valeraldehyde with formaldehyde. The former reactant is synthesized by a two-step reaction from propanal (Figure 5).26 The dicarbamate derivative (meprobamate) was made by reacting the 2-substituted 1, 3-propanediol derivative with phosgene in an inert medium consisting of a tertiary amine acceptor (see Figure 6). This phosgenation process, which was carried out at low temperatures, yields a chlorocarbonate derivative that is ultimately converted to the dicarbamate form. In order to avoid the formation of cyclic carbonates in the reaction vessel, an excess of phosgene must be present.
Ethylene Formation from Methionine and its Analogs
Robert A. Greenwald in CRC Handbook of Methods for Oxygen Radical Research, 2018
The only commercial supplier of KMB that I have found is Sigma Chemical Co. It is listed in their catalog under α-keto-γ-methiolbutyric acid, sodium salt (catalog number K 6000). Methional is also available from Sigma under the name methional, or from Eastman Chemical or Alfa Chemical under the name 3-(methylthio)propionaldehyde. Methional is less expensive than KMB, but beware of its poor solubility in water and permeating odor. Precaution should be taken in storing methional. After breaking the seal on the methional bottle, it is recommended that the tightly capped bottle be placed in a separate container (e.g., a wide-mouth jar with screw cap) and stored in the freezer with sodium bisulfite in the outer container to minimize diffusion of the vile substance throughout the freezer and laboratory. Sodium bisulfite forms a nonvolatile addition product with aldehydes.
Use of Biomarkers in Health Risk Assessment
Anthony P. DeCaprio in Toxicologic Biomarkers, 2006
The second experiment, conducted by Costa et al. (56), investigated the formation of DNA–protein crosslinks by various industrial chemicals in cultured human lymphoma cells. Chemicals investigated included acetaldehyde, acrolein, diepoxybutane, paraformaldehyde, 2-furaldehyde, propionaldehyde, chloroacteldehyde, sodium arsenite, and a deodorant tablet named Mega-Blue (hazardous component listed as tris[hydroxymethyl]nitromethane). In this series of studies, DNA–protein crosslink formation was investigated at two washing temperatures (45 and 65°C). A number of compounds were found to cause the formation of DNA–protein crosslinks at both temperatures, including acrolein, diepoxybutane, paraformaldehyde, and Mega-Blue. In contrast, 2-furaldehyde, acetaldehyde, and proprionaldehyde only produced DNA–protein crosslinks at 45°C. With the exception of two compounds (2-furaldehyde and paraformaldehyde), DNA–protein crosslinks were only observed at concentrations that caused cell death within four days of dosing, suggesting that this biomarker is not suitable for use in environmental exposure scenarios.
Inhibitors of glucosamine-6-phosphate synthase as potential antimicrobials or antidiabetics – synthesis and properties
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Joanna Stefaniak, Michał G. Nowak, Marek Wojciechowski, Sławomir Milewski, Andrzej S. Skwarecki
Another series of l-2,3-diaminopropanoic acid derivatives that exhibit GlcN-6-P synthase inhibiting properties, including compounds 13 and 14 (Scheme 5B and C) were obtained by Walkowiak et al.46 The antifungal activity of these compounds was poor, with MIC values in the 62.5–125 µg/mL range. To obtain compound 13, the authors utilised a condensation reaction between butanal and propionaldehyde diethyl acetate, followed by oxidation and hydrolysis, to obtain ketone 15 (Scheme 5B). The carbonyl group of this ketone intermediate was protected via acetal formation and then treated with TFA to obtain compound 16, which was subsequently coupled with appropriately protected L-norvaline derivative 17 and once again treated with TFA, to finally yield dipeptide 13. On the other hand, compound 14 was prepared via an aldol condensation of 2-acetylpyrrole and 2-oxoacetic acid, which yielded pseudofumarate 18 (Scheme 5C). Carboxylic acid activation using DCC/HOBt and consecutive conjugation of the protected amino acid was performed similarly as in the B route and led to the ultimate formation of 1446.
The effect of electronic cigarettes exposure on learning and memory functions: behavioral and molecular analysis
Published in Inhalation Toxicology, 2021
Karem H. Alzoubi, Rahaf M. Batran, Nour A. Al-Sawalha, Omar F. Khabour, Nareg Karaoghlanian, Alan Shihadeh, Thomas Eissenberg
ECIG aerosols have been shown to contain numerous toxicants including aldehydes (Kosmider et al. 2014; Khlystov and Samburova 2016; Sleiman et al. 2016; Ogunwale et al. 2017; Talih et al. 2020), phenols (Chivers et al. 2019; El-Hage et al. 2020), metals (Williams et al. 2017; Olmedo et al. 2018; Zhao et al. 2019), and reactive oxygen species (Bitzer et al. 2017; 2017; Haddad et al. 2019),. ECIG use can lead to harm through inhalation of the stimulant drug nicotine that can cause dependence, leading to increased exposure to the ECIG aerosol. This results in continued inhalation of toxicants that can be formed when PG and VG are heated (e.g. formaldehyde, acetaldehyde, propanal and acrolein; see (El-Hage et al. 2020; El-Hellani et al. 2018)). These aldehydes can lead to lung and heart disease (Ogunwale et al. 2017). ECIG aerosol exposure can also precipitate several harmful effects such as elevated blood pressure and heart rate (Qasim et al. 2017) and stress-induced mitochondrial hyperfusion in stem cells (Zahedi et al. 2019). A recent study showed that chronic exposure to ECIG aerosols, even without nicotine, negatively impacted lipid homeostasis in the airways and impaired immunity (Madison et al. 2019).
Urinary levels of the acrolein conjugates of carnosine are associated with inhaled toxicants
Published in Inhalation Toxicology, 2020
Timothy E. O’Toole, Xiaohong Li, Daniel W. Riggs, David J. Hoetker, Ray Yeager, Pawel Lorkiewicz, Shahid P. Baba, Nigel G. F. Cooper, Aruni Bhatnagar
The measurement of carnosine and its propanal- and propanol-conjugates was accomplished as previously described (Abplanalp et al. 2019). In brief, urine samples were diluted in a solution of 75% acetonitrile:25% water containing 30 nM 13C9 carnosine as an internal standard. Samples were separated and carnosine and its conjugates were identified using a Waters ACQUITY ultra performance liquid chromatography H-Class System (BEH hydrophilic interaction liquid chromatography column equipped with an in-line frit filter unit) coupled with a Xevo TQ-S micro triple quadrupole mass spectrometer. The analytes were eluted using a binary solvent system consisting of 10 mM ammonium formate, 0.125% formic acid in 50% acetonitrile: 50% water for mobile phase A and 10 mM ammonium formate, 0.125% formic acid in 95% acetonitrile: 5% water for mobile phase B at a flow rate of 0.55 mL/min. Initial conditions were 0.1: 99.9 A: B ramping to 99.9: 0.1 A:B over 5 min then quickly ramping to 0.1:99.9 A:B over 0.5 min (Supplemental Figure 1). Aldehyde conjugates were quantified using the peak ratio of histidyl-dipeptide and 13C9 carnosine internal standard, interpolated using a standard curve and expressed as nmole/mg creatinine.
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