Organic Chemicals
William J. Rea, Kalpana D. Patel in Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
Polyester is usually polyethylene glyco tetraphthalate. It is made from p-xylene and nitric acid. The macromolecule of the polyester formed from tetraphthalic acid and glycol is linked between the two. Approximately 100–150 units are linked together in a polymer. After solidification, the polycondensate is converted to polyester chips, becoming the raw material for polyester fibers.99 The chemically sensitive cannot tolerate materials made of these. Ethylene (oxirane) can also be used as a fumigate and can cause severe reactions in the chemically sensitive and also trigger vasculitis, immune deregulation, chronic fatigue, itching, and severe pain. The case report of A.F. is an example where he had a high propensity of ethylene in addition to 1,3-pentadienes. Some of the functions of ethylene (oxirane, methyl) include fungicide, coatings of integrated circuitry and silicon crucibles, and a blending fuel often enhances the cold-start performance of gasoline and ethanol. Both ethylene and 1,3-pentadiene are often found in the breath analysis of the chemically sensitive.
Environmental Exposures and Reproduction *
Michele Kiely in Reproductive and Perinatal Epidemiology, 2019
The Total Exposure Assessment Methodology study (TEAM) evaluated total exposures to selected volatile organics, semivolatile organics, metals and polyaromatic hydrocarbons for chosen individuals.49 For 11 common indoor chemicals studied (chloroform, 1,1,1-trichloroethane, benzene, carbon tetrachloride, trichloroethylene, tetrachloroethylene, styrene, p-dichlorobenzene, ethylbenzene, o-xylene, and m,p-xylene) overnight indoor air levels in the home were greater than overnight outdoor air levels. In addition, smokers’ homes had benzene levels 30 to 50% higher than non-smokers’ homes. Therefore, air pollution studies which use ambient (outdoor) air measurements may result in misleading findings.
Oxime Research
Brian J. Lukey, James A. Romano, Salem Harry in Chemical Warfare Agents, 2019
The chain linking two quaternary nitrogens in bispyridinium oximes exerts a great effect on the reactivating efficacy, although this part of the oxime does not play any role in the dephosphylation process. It is a major factor in influencing oxime access to the active site of AChE and its reactivation rates. The length of the linker between both pyridinium rings (for bisquaternary pyridinium reactivators) plays an important role in its potency to reactivate nerve agent–inhibited AChE (Kuca et al., 2003c; Pang et al., 2003). There is relationship between the length of the n-methylene linkage chain and the type of nerve agent used for inhibition. The optimal length of the reactivator’s linker for satisfactory potency to reactivate tabun, sarin, or VX-inhibited AChE is three or four methylenes. On the other hand, one methylene group seems to be the most potent for the reactivation of cyclosarin-inhibited AChE. Unfortunately, this rule is satisfied only in the case of n-methylene linkage chains and oxime groups in position four at the pyridinium ring. Compounds with oxygen, sulfur, or other structural fragments differing from the methylene that are incorporated into the linker and compounds with different positions of oxime groups do not fulfill this rule (Acharya et al., 2009b; Musilek et al., 2005, 2006b; Oh et al., 2006; Pang et al., 2003). These differences could be caused by the presence of the free electrons in the linker and subsequent interactions of this part of the reactivator’s molecule with the inside of the enzyme cavity. An important structural factor influencing the reactivation process could also be the “rigidity” of the linking chain. Due to the rigidity of the linker, the spatial orientation of the pyridinium rings in the enzyme cavity is limited. Compounds with a certain level of rigidity of the linker were synthesized with the aim of elucidating the influence of rigidity on reactivation potency. Z- and E-but-2-ene and ortho-, meta-, and para-xylene moieties were inserted into the linkage chain (Musilek et al., 2005, 2006b, 2007b).
Insights into the potential mechanism underlying liver dysfunction in male albino rat exposed to gasoline fumes
Published in Egyptian Journal of Basic and Applied Sciences, 2021
Folarin Owagboriaye, Sulaimon Aina, Rasheed Oladunjoye, Titilola Salisu, Adedamola Adenekan, Gabriel Dedeke
A total of 23 hydrocarbon components were detected in the gasoline used for this study (Supplementary Table S1). Toluene has the highest percentage composition in the gasoline sample. This was followed by o-xylene, naphthalene, undecane, ethylbenzene and p-Xylene. A total of seventeen (17) hydrocarbon components, including gasoline metabolites, were detected in the liver of the experimental rats (Table 3). Benzene was detected in the liver of rats in all the groups. However, benzene level was significantly reduced in group I. Paracyclophane and ethylbenzene were only detected in the liver of rats in group III. Similarly, 4,7-Methano-1 H-indene, Azulene, Cyclobutane, 3-Phenylthiane, Quinoline and 1-benzylindole were only detected in the liver of rats in group V.
Examination of xylene exposure in the U.S. Population through biomonitoring: NHANES 2005–2006, 2011–2016
Published in Biomarkers, 2021
Víctor R. De Jesús, Daniel F. Milan, Young M. Yoo, Luyu Zhang, Wanzhe Zhu, Deepak Bhandari, Kevin S. Murnane, Benjamin C. Blount
Xylenes are aromatic hydrocarbons commonly used for industrial applications due to their superior solvent properties (Angerer and Lehnert, 1979, Mohammadyan and Baharfar 2015). They are synthetically derived from crude oil or coal tar and used in various commercial products such as petrochemicals, plastics, and paints. Additionally, other xylene sources in the environment include landfill gases, emissions from petroleum refineries, vehicle exhaust fumes, and tobacco smoke (Chambers et al.2011, Niaz et al.2015, Staszewska et al.2012, Saliba et al.2017). Xylene exists as three different positional isomers: ortho-, meta-, and para-xylene (o-xylene, m-xylene, and p-xylene). Throughout this report, the term xylene refers to a mixture of the three positional isomers unless otherwise stated.
Noninvasive urine metabolomics of prostate cancer and its therapeutic approaches: a current scenario and future perspective
Published in Expert Review of Proteomics, 2021
Deepak Kumar, Kavindra Nath, Hira Lal, Ashish Gupta
Jiménez-Pacheco et al. executed GC-MS based urine metabolomics study incorporating PC and BPH cohorts. Their findings revealed altered metabolites (Table 2): decreased levels of 3,5-dimethylbenzaldehyde (p = 0.027), 2,6-dimethyl-7-octen-2-ol (p = 0.003), 2-ethylhexanol (p = 0.032), santolintriene (p = 0.032), and increased levels of furan (p < 0.001) in PC urine compared to BPH, collected before prostatic massage. Increased levels of the following were collected after prostatic massage: 3-methylphenol (p = 0.014), phenol (p < 0.001), furan (p < 0.001), 2-butanone (p < 0.001), and p-xylene (p < 0.002) in PC urine compared to BPH. Pre- and post-massage urinary furan levels were not found correlated to the Gleason score. However, 3-methylphenol, phenol, 2-butanone, and p-xylene levels were found to be positively correlated with the Gleason score. The study projected that urinary furan and p-xylene may be potential biomarkers for PC [71].
Related Knowledge Centers
- Aromatic Compound
- Naphtha
- Polymer
- Xylene
- Arene Substitution Pattern
- Parts-Per Notation
- Catalytic Reforming
- Btx
- Ethylbenzene
- Eutectic System