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Lifestyle and Diet
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
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).
Gas Chromatographic Analysis
Published in Adorjan Aszalos, Modern Analysis of Antibiotics, 2020
Margosis [36] extracted with cyclohexane from 5% NaOH. Naphthalene was used as internal standard. The experimental conditions were injection port at 60°C, column (3% OV-17 on Gas Chrom Q 100/120) at 60°C, and FID at 150°C. The column had to be silylated by injection of a silyl reagent with the temperature at 275°C prior to the analysis. At the level of 1.7 ppm of N,N-dimethylaniline in antibiotic, the CV was 7.9. The limit of detection was about 0.5 ppm. Amounts found in commercial samples ranged up to 1500 ppm.
The Application of Fragment-based Approaches to the Discovery of Drugs for Neglected Tropical Diseases
Published in Venkatesan Jayaprakash, Daniele Castagnolo, Yusuf Özkay, Medicinal Chemistry of Neglected and Tropical Diseases, 2019
Christina Spry, Anthony G. Coyne
To demonstrate the utility of CrystalDock, an algorithm designed to identify fragments likely to bind a protein pocket, Durrant et al. (2011) used the algorithm to identify fragments likely to bind to the adenylation domain of T. brucei RNA editing ligase 1 (TbREL1). The algorithm identified three clusters of fragments likely to bind in the TbREL1 active site. One cluster of hydrophobic fragments was interestingly predicted to bind in close proximity to the predicted binding site of a low-μM naphthalene-based inhibitor (Durrant et al. 2010), in a small pocket not previously exploited for drug discovery. This presented the opportunity to improve the affinity of the naphthalene-based inhibitor through fragment linking. One of the hydrophobic fragments—a toluene fragment (Table 1)—was positioned such that it could be linked via a methylene linker to the inhibitor. Subsequent binding energy calculations are consistent with the elaborated inhibitor (Table 1) binding with higher affinity; however, this needs to be experimentally validated.
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.
Design, synthesis and biological evaluation of novel thiazole-naphthalene derivatives as potential anticancer agents and tubulin polymerisation inhibitors
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2021
Guangcheng Wang, Wenjing Liu, Meiyan Fan, Min He, Yongjun Li, Zhiyun Peng
On the other hand, naphthalene is a prominent core structure in many anticancer agents. A number of naphthalene derivatives have been reported as potent inhibitors of tubulin (Figure 1, V–VIII)22–25. Such as Maya et al. reported the synthesis of a series of new naphthalene analogues of combretastatin A-4 (CA-4) and the most cytotoxic naphthalene analogues V exerted tubulin polymerisation inhibition activity and arrest cell cycle in G2/M phase in human cancer cells25. Based on the lead compound HMNC-74, we synthesised a series of new naphthalene-chalcone derivatives and evaluated their anticancer activity. Among them, compound IV was the most potent tubulin polymerisation inhibitor with an IC50 value of 8.4 μM23. Recently, we have also reported a new series of benzophenone derivatives bearing naphthalene moiety, and compound VII displayed potent antiproliferative activity against various cancer cell lines by targeting tubulin colchicine binding site24. Furthermore, we also designed a new series of chalcones containing naphthalene moiety (VIII) based on natural tubulin inhibitor millepachine22,26.
In vitro abrasivity and chemical properties of charcoal-containing dentifrices
Published in Biomaterial Investigations in Dentistry, 2020
Foteini Machla, Aida Mulic, Ellen Bruzell, Håkon Valen, Ida Sofia Refsholt Stenhagen
The presence of naphthalene in NAO is unsurprising as naphthalene is reported as the most abundant PAH in biochar (product of pyrolysis used for agricultural and environmental applications rather than fuel) [34]. According to European Union regulation, the presence of naphthalene in cosmetic products is prohibited [35]. The toxicity of naphthalene is outlined in a report by the National Toxicology Program [36]. A limitation of the present study was that the presence of PAHs only was investigated in these charcoal-containing dentifrices. An alternative extraction protocol (Soxhlet extraction) or the use of liquid chromatography–mass spectrometry (LC-MS) rather than GC-MS may have revealed other PAHs [37]. LC-MS is normally capable of achieving lower limits of detection compared to GC-MS, depending on the molecular weight of the compound of interest. Elemental analysis of coconut-based charcoals used in waterpipes showed larger amounts of heavy metals (lead, zinc, iron, cadmium, aluminum, cobalt and chromium) compared to the content of cigarettes, therefore, the presence of other hazardous substances cannot be disregarded [38]. Furthermore, only one batch of each dentifrice was used and the country of origin of the charcoal was unknown. Thus, it is also reasonable to expect variation between batches or types of charcoal-based dentifrices [39].