Search results for "Aromatic hydrocarbon"

Mammalian Xenobiotic Epoxide Hydrolases

2002

Reversible, room-temperature C—C bond activation of benzene by an isolable metal complex

2019

The activation of C-C bonds is of fundamental interest in the construction of complex molecules from petrochemical feedstocks. In the case of the archetypal aromatic hydrocarbon benzene, C-C cleavage is thermodynamically disfavored, and is brought about only by transient highly reactive species generated in situ. Here we show that the oxidative addition of the C-C bond in benzene by an isolated metal complex is not only possible, but occurs at room temperature and reversibly at a single aluminium center in [(NON)Al]- (where NON = 4,5-bis(2,6-diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene). Selectivity over C-H bond activation is achieved kinetically and allows for the generation…

Fate of Epdxides

1982

One of the most important reactions of epoxides appears to be the covalent binding to DNA which can lead to mutagenicity and is strongly suspected to be the primary lesion ultimately leading to initiation of cancer (Miller and Miller, 1974; Oesch, 1973; Jerina and Daly, 1974; Sims and Grover, 1974; Heidelberger, 1975; Gelboin et al., 1972). This review first describes structure-activity relationships for the mutagenicity of some epoxides and then outlines some findings on the metabolic control of the concentration of such epoxides by a number of enzymes.

Selective recognition of aromatic hydrocarbons by endo-functionalized molecular tubes via C/N-H⋅⋅⋅π interactions

2018

Abstract Molecular recognition of aromatic hydrocarbons by four endo -functionalized molecular tubes has been studied by 1 H NMR spectroscopy, computational methods, and single crystal X-ray crystallography. The binding selectivity is rationalized by invoking shape complementarity and dipole alignment. The non-covalent interactions are proved to predominantly be C/N-H⋅⋅⋅ π interactions.

Isolation, separation and quantification of metabolites of the carcinogenic polycyclic aromatic hydrocarbon dibenz(a,h)anthracene

1986

Occurrence and removal of organic pollutants in sewages and landfill leachates

2002

Sewages of different composition and the effluents of four sewage treatment plants (STPs), plus sewage sludges were analysed for semivolatile organic priority pollutants. Furthermore, 11 landfill leachates were analysed to evaluate their contribution to sewage pollutants when co-treated. Bis(2-ethylhexyl) phthalate (DEHP) was the pollutant occurring at highest concentrations (up to 122 microg/l) and it was present in all sewages and leachates; concentrations of other phthalates were usually below 17 microg/l. Some polycyclic aromatic hydrocarbons (PAH) (<1 microg/l) and 2,6-dinitrotoluene (< or =5.9 microg/l) were also present in many of the sewages and leachates. Phthalates were present in…

Risk assessment of exposure to organic chemicals in children and mothers using human biomonitoring

2022

Today, global chemical manufacturing is increasing each year, making environmental pollution and exposure to chemicals a serious public health problem linked to the development of many non-genetic diseases. Approximately, 70 % of chemicals consumed in Europe in 2019 were hazardous for human health. These harmful substances can enter to the food chain and remain in the environment, making humans exposed to them mainly by ingestion, inhalation or dermal exposure. Consequently, exposure to chemicals should be continuously monitored for assuring health protection of citizens by two ways: i) studying their presence in environmental compartments, such as water, food, soil or air, by environmental…

Selective recognition of aromatic hydrocarbons by endo-functionalized molecular tubes via C/N-H⋅⋅⋅π interactions

2018

Molecular recognition of aromatic hydrocarbons by four endo-functionalized molecular tubes has been studied by 1H NMR spectroscopy, computational methods, and single crystal X-ray crystallography. The binding selectivity is rationalized by invoking shape complementarity and dipole alignment. The non-covalent interactions are proved to predominantly be C/N-H⋅⋅⋅π interactions. peerReviewed

Hazardous air pollutants and primary liver cancer in Texas.

2016

The incidence of hepatocellular carcinoma (HCC), the most common primary liver cancer, is increasing in the US and tripled during the past two decades. The reasons for such phenomenon remain poorly understood. Texas is among continental states with the highest incidence of liver cancer with an annual increment of 5.7%. Established risk factors for HCC include Hepatitis B and C (HBV, HCV) viral infection, alcohol, tobacco and suspected risk factors include obesity and diabetes. While distribution of these risk factors in the state of Texas is similar to the national data and homogeneous, the incidence of HCC in this state is exceptionally higher than the national average and appears to be di…

Dicyclopentaannelated Hexa-peri-hexabenzocoronenes with a Singlet Biradical Ground State

2021

Abstract Synthesis of two dicyclopentaannelated hexa‐peri‐hexabenzocoronene (PHBC) regioisomers was carried out, using nonplanar oligoaryl precursors with fluorenyl groups: mPHBC 8 with two pentagons in the “meta”‐configuration was obtained as a stable molecule, while its structural isomer with the “para”‐configuration, pPHBC 16, could be generated and characterized only in situ due to its high chemical reactivity. Both PHBCs exhibit low energy gaps, as reflected by UV‐vis‐NIR absorption and electrochemical measurements. They also show open‐shell singlet ground states according to electron paramagnetic resonance (EPR) measurements and density functional theory (DFT) calculations. The use of…