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Drug Design, Synthesis, and Development
Published in Nathan Keighley, Miraculous Medicines and the Chemistry of Drug Design, 2020
When it comes to building a drug molecule, carbonyl chemistry offers a rich variety of reactions that can be used to create new functional groups, or make new carbon-carbon bonds, which are so important for combining different molecular fragments together that comprise the final target compound. Ketones and aldehydes are versatile functional groups and will undergo a diversity of reactions. The electronegative oxygen polarises the C=O bond, making the C susceptible to nucleophiles and the αH easily deprotonated with a base. Predominantly, ketones and aldehydes will undergo nucleophilic addition reactions; this includes reduction with hydrides to an alcohol and addition of nucleophiles to the carbonyl carbon. A range of nucleophiles can be used, including alcohols, amines, and cyanide, which are particularly useful in synthesis to introduce new functional groups, and Grignard’s reagent to make a new C–C bond. All of these basic organic reactions of carbonyls are invaluable for building a target compound.
Fixation and Tissue Pretreatment
Published in Lars-Inge Larsson, Immunocytochemistry: Theory and Practice, 2020
This dialdehyde (OHC-CH2-CH2-CH2-CHO) was introduced by Sabatini et al.107 as a fixative for electron microscopy. It has rapidly become the fixative of choice for such studies due to its effective cross-linking ability and preservation of several enzyme activities. Being an aldehyde it reacts with amino groups, sulfhydryl groups, and probably with aromatic ring structures.14,40,49,95 As stated for formaldehyde, the extent of the reaction in tissue is largely unknown, however (see the reviews by Hayat42 and Hopwood49). Nevertheless, direct cytochemistry reveals that all detectable ε-amino groups of lysine react with aldehyde fixatives.52 Therefore, particularly with glutaraldehyde, major interference with epitopes rich in lysines (and probably arginines) may be expected.
The Toxic Environment and Its Medical Implications with Special Emphasis on Smoke Inhalation
Published in Jacob Loke, Pathophysiology and Treatment of Inhalation Injuries, 2020
Jacob Loke, Richard A. Matthay, G. J. Walker. Smith
Several aldehydes including formaldehyde, acetaldehyde, and acrolein are among the noxious and irritant gases generated from pyrolysis and combustion in a fire. Aldehydes are irritants to the skin, the eyes, and the mucous membranes, and they cause denaturation of proteins and injury to the lung resulting in pulmonary edema and death. In an analysis of wood smoke and smoke from kerosene, greater amounts of carbon monoxide and aldehydes were present in wood smoke than in kerosene smoke (Zikria et al., 1972). Furthermore, Zikria et al. (1972) showed that animals exposed to wood smoke died with significant pathological findings in the lungs at autopsy. The kerosene smoke-exposed animals survived with less pulmonary injury.
Aldehyde toxicity and metabolism: the role of aldehyde dehydrogenases in detoxification, drug resistance and carcinogenesis
Published in Drug Metabolism Reviews, 2019
Amaj Ahmed Laskar, Hina Younus
Aldehydes are a large class of organic compounds having a carbonyl carbon atom substituted with at least one hydrogen atom along with additional functional moieties. Aldehyde family is generally represented by R-CHO, where R is any functional moiety/carbon-containing substituent. Based on the nature of R group, aldehydes are divided into different subclasses. Broadly, they are classified into aliphatic and aromatic aldehydes which can be either saturated or unsaturated (Feron et al. 1991; Koren and Bisesi 2003). The different subclasses of aldehydes are (i) short chain aldehydes such as formaldehyde, acetaldehyde; (ii) long chain aldehydes such as hexanal, nonanal; (iii) aromatic aldehydes such as cinnamaldehyde, benzaldehyde; (iv) α,β-unsaturated aldehydes such as citral, acrolein; and (v) α-oxoaldehydes such as glyoxal, glycolaldehyde (O’Brien et al. 2005; LoPachin and Gavin 2014).
Acetaldehyde production by Rothia mucilaginosa isolates from patients with oral leukoplakia
Published in Journal of Oral Microbiology, 2020
Abdrazak Amer, Aine Whelan, Nezar N. Al-Hebshi, Claire M. Healy, Gary P. Moran
Two methods of aldehyde detection were used. Firstly, a colorimetric aldehyde detection assay kit (Sigma-Aldrich, Co. Wicklow, Republic of Ireland) was used for total aldehyde quantification. Secondly, to verify these data and to specifically detect ACH, we also applied solid phase microextraction (SPME) with Gas chromatography-mass spectrometry (GC-MS) to indicated samples. We analysed 8 strains of R. mucilaginosa including the reference strain R. mucilaginosa DY-18 (DSM-20746). Several common oral microbes were included as controls, including Streptococcus mitis NCTC12261, Streptococcus gordonii DL1, Neisseria mucosa DSM-17611 and Candida albicans 132A.
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
A large body of epidemiological and experimental evidence has identified associations between exposure to air pollution and adverse health outcomes (Pope et al. 2004; Bhatnagar 2006; Chen et al. 2008). Air pollution is a complex mix of particles, gases, and metals. High levels of these components are found in vehicle exhausts, factory emissions, and the combustion of carbonaceous material. Involuntary exposure to these ubiquitous air-borne toxicants contributes to local and systemic oxidative stress, and the subsequent in vivo generation of oxidized lipids (e.g., aldehydes) and electrophilic intermediates. Indeed, it has been shown that exposure to fine particulate matter (PM2.5) air pollution results in the generation of lipid peroxidation products (Kampfrath et al. 2011) and that some the adverse outcomes of PM2.5 exposure can be mitigated by measures taken to reduce oxidative stress (Cui et al. 2015; Haberzettl et al. 2016; 2018). Humans are also directly exposed to existing, environmental sources of aldehydes. Cigarette smoke, for instance, is estimated to contain over 5000 compounds and among the most abundant of these constituents, are several highly reactive aldehydes including acrolein (Brunnemann et al. 1990; Dong and Moldoveanu 2004). High levels of reactive aldehydes are similarly generated during the use of electronic nicotine delivery devices (ENDs) (Keith et al. 2020). As with PM2.5 inhalation, some of the adverse health consequences attributed to the use of cigarettes are likewise believed to result from exposure to aldehydes and other toxic compounds. Regardless of their source, efforts taken to curtail the production or impact of oxidized lipids would seem to mitigate the adverse health impacts of exposure.