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Central Nervous System Effects of Essential Oil Compounds
Published in K. Hüsnü Can Başer, Gerhard Buchbauer, Handbook of Essential Oils, 2020
Elaine Elisabetsky, Domingos S. Nunes
The two most important characteristics of the α,β-unsaturated carbonyl of compounds 21, 23, 24, and 26–29 are the electronic resonance that renders planar different extensions of these molecular structures and the negative charge over the carbonyl oxygen, stronger in 22 and 25, which possess α,β-saturated carbonyls. The carbonyl compounds group presents as a structural characteristic a bigger planar proportion of the molecule, highlighting the structure of compounds 21, 24, 26, 27, and 28, with different capacities as HB acceptors.
The Modification of Lysine
Published in Roger L. Lundblad, Chemical Reagents for Protein Modification, 2020
The modification of primary amines in proteins by reductive alkylation has proved to be a useful reaction (Figure 32). This reaction has the advantage that the basic charge properties of the modified residue are preserved. The early work on this modification has been reviewed by Means and co-workers.97 Both monosubstituted and disubstituted derivatives can be prepared depending upon reaction conditions and the nature of the carbonyl compound.
Free Radical Damage and Lipid Peroxidation
Published in Robert G. Meeks, Steadman D. Harrison, Richard J. Bull, Hepatotoxicology, 2020
Richard O. Recknagel, Eric A. Glende, Robert S. Britton
Thus, once lipid peroxidation is initiated, the process can be propagated via autocatalysis, which is dependent not only on oxygen, but on metal catalyzed decomposition of transiently appearing lipid hydroperoxides. Eventual decomposition of the peroxidized fatty acids gives rise to a variety of stable end products. Endoperoxide decomposition yields malonic dialdehyde (Figure 4), easily detected in the widely used thiobarbituric acid (TBA) test (Recknagel et al., 1982). A variety of other carbonyl compounds also appear (Esterbauer, 1985), some of which are toxic (Benedetti et al., 1980, and see below). Peroxidative decomposition of lipids also yields ethane, from omega-3 fatty acids, e.g., linolenic acid; and pentane, from omega-6 fatty acids, e.g., linoleic acid (Sevanian and Hochstein, 1985; Horton and Fairhurst, 1987). Gas chromatographic detection of these short-chain hydrocarbons in exhaled air of experimental animals has proven to be a powerful noninvasive technique for monitoring lipid peroxidation in vivo (Wendel, 1987).
The protective effect of N-acetyl cysteine against selenium toxicity and gamma irradiation in rats
Published in Drug and Chemical Toxicology, 2023
Riham Abdel-Hamid Haroun, Nahed Abdel-Aziz, Soha Saad
It is well known that both the IR and Se toxicity increase the level of ROS and lipid peroxidation (Lafin et al. 2019, Lei et al. 2020). The lipid peroxidation resulting in the release of a variety of reactive carbonyl compounds, which have high reactivity with the protein-SH groups through Michael addition at the β-carbon of the double bond (R-CH = CH-CHO). The SH-group of NAC can react with these compounds, preventing their conjugation to proteins and therefore alleviating their toxic effects (Zhitkovich 2019). This explains the decreased level of LPO in Rad + NAC group and Se + NAC group relative to Rad group and Se group; respectively. Several studies have reported that NAC prevents oxidative damage and promotes the synthesis of GSH in cells (Paintlia et al. 2008, Astiz et al. 2012, Samuni et al. 2013), which is consistent with our results as the levels of GSH content and GPx enzyme activity were significantly increased in the liver and adrenal gland tissues Rad + NAC group and Se + NAC group when compared to Rad group and Se group, respectively. Also, it is in agreement with Alnahdi et al. (2019) who reported that NAC can attenuate the oxidative/nitrosative stress and GSH-dependent redox imbalance in pancreatic cells. As consistent with previous studies, our results revealed that the activity of SOD was increased in the liver and adrenal gland tissues Rad + NAC group and Se + NAC group when compared to Rad group and Se group, respectively (Ceylan et al. 2018, Chaves Cayuela et al. 2020).
Polymer drug conjugates containing memantine, tacrine and cinnamic acid: promising nanotherapeutics for the treatment of Alzheimer’s disease
Published in Journal of Microencapsulation, 2023
Tobeka Naki, William Morwa Reagile Matshe, Mohammed Olusegun Balogun, Suprakas Sinha Ray, Samuel Ayodele Egieyeh, Blessing Atim Aderibigbe
Michael addition polymerisation is a flexible synthetic approach useful for generating polymers ranging from linear to hyperbranched polymers (Sun et al. 2017). Aqueous Michael’s addition polymerisation technique was used to synthesise the polymer-drug conjugates in this study. The conjugates are prepared in water in a one-pot process and are characterised by linear architectures. The reaction involves a nucleophilic addition of a nucleophile to an α, β-unsaturated carbonyl compound. Under mild reaction conditions, the reaction is useful for forming C–C bonds. The advantages of Michael addition reactions are high conversions, the capability to accommodate high functional groups and favourable reaction rates (Aderibigbe et al. 2020). The aza Michael polyaddition of prim-monoamines or bis-sec-amines with bis-acrylamides yields a synthetic polymer called linear polyamidoamines (PAAs) (Marcioni et al. 2021). PAAs are polymeric carriers with high structural flexibility. They can be engineered to be biodegradable and biocompatible, and are mostly highly water-soluble and hydrophilic. Their capability to hydrolytically degrade in aqueous systems arise from the amide bond on their backbone. Most of them have demonstrated promising antiviral activity, useful as sensor constituents, heparin complexing agents, heavy metal ion complexing agents, transfection promoters and drug delivery systems (Coué and Engbersen 2011, Marcioni et al. 2021). Polymer-drug conjugates are nanoscale systems in which a drug molecule is covalently attached to a polymer backbone (Duro-Castano et al.2015).
Toxicological assessment of electronic cigarette vaping: an emerging threat to force health, readiness and resilience in the U.S. Army
Published in Drug and Chemical Toxicology, 2022
Marc A. Williams, Gunda Reddy, Michael J. Quinn, Amy Millikan Bell
The purpose of an e-cig is to deliver nicotine to the user’s lungs efficiently and promptly via a respirable aerosol that is liberated from the e-liquid. In most e-cigs, the nicotine is dissolved in the humectant, which is usually a mixture of propylene glycol with or without glycerol (glycerin). Several studies have focused on the chemical components found in e-cigs in addition to the concern with regard the presence of nicotine (Goniewicz et al.2014a, Schober et al.2014a, 2014b, McRobbie et al.2015, Herrington and Myers 2015). These studies have collectively asserted that e-cig users are exposed to carbonyl compounds, formaldehyde and other aldehydes, heavy and transition metals, volatile organic compounds (VOCs), fine and ultrafine particulate matter and humectants among a myriad of other chemical constituents (Pellegrino et al.2012, Bekki et al.2014, Williams et al.2013, Jensen et al.2015, Uchiyama et al.2013, Orr 2014, Callahan-Lyon 2014, Cheng 2014).