Lifestyle and Diet
Chuong Pham-Huy, Bruno Pham Huy in Food and Lifestyle in Health and Disease, 2022
Mothballs are sold as small white balls containing 99.9% either of naphthalene or paradichlorobenzene (PDCB), both of which become a gas with pungent odor when exposed to air. Mothballs are used to repel moths in clothing and stored carpets and to keep pests out of the house (170). The majority of exposure to naphthalene in the environment occurs through inhalation, while other pathways such as dermal contact and ingestion are rare. Naphthalene is recently classified as a possible human carcinogen (171–172). Naphthalene exposure can cause hemolytic anemia due to destruction of red blood cells with apparition of jaundice and pallor. It is also neurotoxic. Small children may eat mothballs, thinking them candy (170). Para-dichlorobenzene (PDCB) is another ingredient of mothballs used as deodorizers and fumigants. PDCB toxicity can affect liver, kidneys, skin, lungs, and the central nervous system (CNS). Chronic toxicity of PDCB often results in leukoencephalopathy, ataxia, and heterogeneous neurological manifestations (173–175). Mothballs containing either PDCB or naphthalene, can cause cancer in animals, and are potential human carcinogens (170–172). So, be careful when using mothballs as moth or pest repellents. Due to the toxicity of naphthalene and para-dichlorobenzene, avoid the use of mothballs if you have a chronic disease, or infants and children in the house. Replace mothballs by cedar chips (170).
Multi-Functional Monoamine Oxidase and Cholinesterase Inhibitors for the Treatment of Alzheimer’s Disease
Peter Grunwald in Pharmaceutical Biocatalysis, 2019
Compounds 24 and 25, Fig. 11.19, were built from the N-benzylpiperidine and propargylamine moieties and connected through an appropriate linker to a central pyridine (24) or naphthyridine ring (25). The compounds were shown to be equipotent with donepezil and more potent than tacrine for eeAChE inhibition. All compounds were less potent that the reference compound for BuChE inhibition with IC50 values over 100 μM. For the naphthalene compounds inhibition of both ChEs increased with increased chain length. The latter also applied to MAO inhibition. This article concluded that in as much as this specific combination of moieties is not the best for multi-potent compounds, they established the importance of spacer length in interaction with both the CAS and PAS of AChE (Samadi et al., 2011).
Outdoor Emissions
William J. Rea, Kalpana D. Patel in Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
The main components of crude oil are aliphatic and aromatic hydrocarbons. Lower-molecular-weight aromatics, such as benzene, toluene, and xylene, are VOCs and evaporate within hours after the oil reaches the surface. VOCs can cause respiratory irritation and CNS depression. Benzene is known to cause leukemia in humans, and toluene is a recognized teratogen at high doses. Higher-molecular-weight chemicals such as naphthalene evaporate more slowly. Naphthalene is “reasonably anticipated to cause cancer in humans” based on olfactory neuroblastomas, nasal tumors, and lung cancers in animals. Oil can also release hydrogen sulfide gas and contains traces of heavy metals, as well as nonvolatile PAHs that can contaminate the food chain. Hydrogen sulfide gas is neurotoxic and has been linked to both acute and chronic CNS effects; PAHs include mutagens and probably carcinogens. Burning oil generates PM, which is associated with cardiac and respiratory symptoms and premature mortality. The Gulf oil spill is unique because of the large-scale use of dispersants to break up the oil slick. By late July, more than 1.8 million gallons of dispersant had been applied in the Gulf. Dispersants contain detergents, surfactants, and petroleum distillates, including respiratory irritants such as 2,1-butoxyethanol, propylene glycol, and sulfonic acid salts. In addition to oil and its products (Chapter 6), these dispersants cause havoc with the chemically sensitive, causing an exacerbation of their symptoms (Figures 1.10 and 1.11).
The association between urinary polycyclic aromatic hydrocarbon metabolites and atopic triad by age and body weight in the US population
Published in Journal of Dermatological Treatment, 2022
Sooyoung Kim, Kathryn A. Carson, Anna L. Chien
1-NAP comprises the largest proportion of all PAH metabolites. Naphthalene metabolizes to 1-NAP which is commonly emitted from household products such as deodorizers, insecticides, and carpeting as well as cigarette smoke, vehicle exhaust, and fireplaces (17). Moreover, naphthalene is classified as a class 2B carcinogen by the International Agency for Research on Cancer (17). We found that 1-NAP increased the risk of wheezing in children and adults as well as increased the risk of sneezing in children. The associations of 1-NAP on wheezing and sneezing, especially in children, imply non-occupational exposure to naphthalene in daily life. Naphthalene exposure occurs almost exclusively by inhalation, with approximately 2% in the particulate phase serving as a surrogate marker of air pollution (18). Careful investigation of daily life exposure (i.e. secondhand smoke) to naphthalene, especially in children, is warranted.
Scaffold hopping and optimisation of 3’,4’-dihydroxyphenyl- containing thienopyrimidinones: synthesis of quinazolinone derivatives as novel allosteric inhibitors of HIV-1 reverse transcriptase-associated ribonuclease H
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2020
Graziella Tocco, Francesca Esposito, Pierluigi Caboni, Antonio Laus, John A. Beutler, Jennifer A. Wilson, Angela Corona, Stuart F. J. Le Grice, Enzo Tramontano
Synthesis of 4-(naphthalen-2-yl)benzene-1,2-diol (23). To a mixture of 2-naphtylboronic acid (5.81 mmol), K2CO3 (5.81 mmol), and Pd(OAc)2 (0.048 mmol) in ethanol (15 ml) and water (5 ml) was slowly added 4-bromo-1,2-dimethoxybenzene (4.84 mmol). The mixture was stirred at room temperature for 18 h. To the resulting mixture was added water (80 ml), and then extracted with dichloromethane. The organic phase was separated, dried over Mg2SO4 and concentrated under reduced pressure to give a solid residue which was purified by flash chromatography (silica gel, hexane/ethyl acetate 5/1). The pure 2–(3,4-dimethoxyphenyl)naphthalene was obtained as white solid and used for the next reaction. Yield (%) = 93. 1H NMR (500 MHz, DMSO): δ 8.29 (d, J = 8.0 Hz, 1H), 8.12 (d, J = 8.0 Hz, 1H), 7.98 (d, J = 7.4 Hz, 1H), 7.82 (t, J = 8.0 Hz, 1H), 7.75 (t, J = 8.0 Hz, 1H), 7.61 (s, 1H), 7.45 (d, J = 8.2 Hz, 1H), 7.39 (d, J = 7.4 Hz, 1H), 7.12 (s, 1H), 7.02 (d, J = 8.2 Hz, 1H), 3.85 (s, 3H), 3.78 (s, 3H) ppm. 13 C NMR (500 MHz, DMSO): δ 151.20, 148.19, 139.45, 135.45, 132.13, 127.00, 124.15, 119.32, 117.56, 116.03, 113.40, 112.26, 110.67, 108.65, 57.23 ppm. HRMS calculated for C18H16O2 264.12 found 264.12.
Comparative toxicity of selected PAHs in rainbow trout hepatocytes: genotoxicity, oxidative stress and cytotoxicity
Published in Drug and Chemical Toxicology, 2020
Mazyar Yazdani
Exposure to naphthalene caused significantly increased cytotoxicity (reduced membrane integrity) as compared with the control at all concentrations (Figure 3), but the differences were only significant at concentrations ≥0.1 µM. There was no cytotoxicity following exposure to any of the tested concentrations of fluoranthene and B[a]P. Pyrene appeared to give rise cytotoxicity in trout hepatocytes at all exposure concentrations.
Related Knowledge Centers
- Aromaticity
- Benzene
- Coal Tar
- Distillation
- Naphtha
- Organic Chemistry
- Organic Compound
- Polycyclic Aromatic Hydrocarbon
- Parts-Per Notation
- Mothball