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Monographs of fragrance chemicals and extracts that have caused contact allergy / allergic contact dermatitis
Published in Anton C. de Groot, Monographs in Contact Allergy, 2021
Heptanal is a colorless clear liquid; its odor type is green and its odor at 1% in dipropylene glycol is described as ‘fresh aldehydic fatty green herbal wine-lee ozone’ (www.thegoodscentscompany.com). The chemical is or has been used in the manufacture of 1-heptanol, organic synthesis, perfumery, pharmaceuticals, and flavoring (U.S. National Library of Medicine).
Lung macrophages: current understanding of their roles in Ozone-induced lung diseases
Published in Critical Reviews in Toxicology, 2020
While the ELF layer serves to protect the mucosal surfaces of the respiratory tract from inhaled agents, molecular interactions between O3 and constituents of the ELF layer result in the generation of harmful ozonation products. Studies employing radioactive oxygen (18O) labeled O3 revealed a higher concentration of 18O in the ELF suggesting its incorporation into ELF biomolecules (Hatch et al. 1994). The incorporation of O3 into the unsaturated carbon backbone of ELF constituents, including phospholipids, cholesterol, epoxy cholesterol, proteins, and hyaluronic acids (HA), leads to a rapid drop in its levels within the ELF layer before it reaches the epithelial cells (Johnson 1980; Gordon et al. 1981; Sharman and Mudd 1981; Friedman et al. 1985; Madden et al. 1987). Through the Criegee reaction, ozonation of unsaturated fatty acids yields aldehydes, such as hexanal, nonanal, heptanal, and carbonyl oxide. These aldehydes have been shown to be elevated in the BALF of O3-exposed humans and rats (Pryor et al. 1996; Frampton et al. 1999a, 1999b). Among these, carbonyl oxide, being a reactive species, further combines either with aldehydes to form ozonide (incorporation of O3 in carbon–carbon chain) or with water to form hydroxy hydroperoxide in aqueous environments (Santrock et al. 1992).
Can Plasmodium’s tricks for enhancing its transmission be turned against the parasite? New hopes for vector control
Published in Pathogens and Global Health, 2019
S. Noushin Emami, Melika Hajkazemian, Raimondas Mozūraitis
It is well documented that mosquito search behavior for hosts is triggered by olfactory perception of VOCs emitted from animals and humans [30,42,43]. Plasmodium parasites are able to increase the infected host attraction to vectors by manipulating host-VOC profiles [30,44]. A recent study demonstrated increases in the production of the heptanal, octanal, nonanal, (E)-2-octenal, (E)-2-decenal and 2-octanone by malaria parasite-infected Kenyan children. Increases were broadly associated with infections with high malaria parasite load, compared to patients having either low malaria parasite density or being parasite-free [44]. Kelly et al. [45] reported that P. falciparum infected erythrocytes released few VOCs under in vitro culture conditions. Amounts of the monoterpene, α-pinene, were higher in the samples containing erythrocytes infected by P. falciparum strain 3D7-MR4 at 2% parasitemia compared to those bearing uninfected erythrocytes as well as to the samples containing infected erythrocytes treated with 5 µM of fosmidomycin [45], an inhibitor of parasite isoprenoid biosynthesis by affecting the first enzyme of the MEP pathway, deoxyxylulose phosphate reductoisomerase [46, 47]. Identification of other four compounds, namely, 3,5-bis (1,1-dimethylethyl)-4-methyl-1H-pyrazole, 6-hydroxy-5,7-dimethoxy-naphtho[2,3-c]furan-1(3H)-one, 4,5,9,10-dehydro-isolongifolene and 8,9-dehydro-9-formyl cycloisolongifolene is putative, due to insufficient match factors of mass spectra obtained from analytes and those available in electronic libraries as well as the absence of standards during identification [45]. Recently, Emami and colleagues [11] showed that a P. falciparum-derived compound, HMBPP, significantly enhances the release of CO2 by 16% in the headspace of treated erythrocytes compared to untreated cells. HMBPP addition also increased the release of three monoterpenes, α- and ß-pinene and limonene by 1.2-to-1.6 fold as well as three aldehydes octanal, nonanal and decanal by 1.7-to-5.2 fold. A mixture of all seven components was essential to trigger the host-seeking behavior of An. gambiae s.s. under laboratory conditions. These findings suggest the mechanism which underpins the Plasmodium’s requirement to manipulate their mosquito hosts in order to elevate the odds of infection to a degree sufficient for success at sustained transmission. These elements of the chemical signaling belonged to three main categories of volatiles, CO2, aldehydes and terpenes and appear highly evolved between these parasites and their definitive hosts, suggesting a powerful selection and survival advantage linked to it [11].