CAS No.: 17088-22-1
Inquire 1-Ethylpyrene (cas: 17088-22-1 ) online by filling out the inquiry form, we will get back to you within 24 hours!
For research use only. Not Intended for Therapeutic Use!
We would like to match the lowest price on market if possible.
. Carcinogenesis. 1999 Sep;20(9):1777-85. doi: 10.1093/carcin/20.9.1777.
Benzylic hydroxylation of 1-methylpyrene and 1-ethylpyrene by human and rat cytochromes P450 individually expressed in V79 Chinese hamster cells.
Engst W(1), Landsiedel R, Hermersdörfer H, Doehmer J, Glatt H.
Author information: (1)Deutsches Institut für Ernährungsforschung (DIfE), Department of Toxicology, Arthur-Scheunert-Allee 114-116, D-14558 Bergholz-Rehbrücke, München, Germany.
Alkyl-substituted polycyclic aromatic hydrocarbons may be metabolized to highly reactive benzylic sulfuric acid esters via benzylic hydroxylation and subsequent sulfonation. We have studied the benzylic hydroxylation of 1-methylpyrene (MP), a hepatocarcinogen in rodents, and 1-ethylpyrene (EP), whose benzylic hydroxylation would produce a secondary alcohol (alpha-HEP), in contrast to the primary alcohol (alpha-HMP) formed from MP. The hydrocarbons were incubated with hepatic microsomal preparations from humans and rats, as well as with V79-derived cell lines engineered for the expression of individual cytochrome P450 (CYP) forms from human (1A1, 1A2, 1B1, 2A6, 2E1, 3A4) and rat (1A1, 1A2, 2B1). All microsomal systems and CYP-expressing cell lines used, but not CYP-deficient V79 cells, showed biotransformation of both hydrocarbons. Formation of the benzylic alcohol was detected in each case. alpha-HMP and its oxidation product, 1-pyrenylcarboxylic acid (COOH-P), accounted for a major part of the total amount of the metabolites formed from MP in the presence of human liver microsomes (38-64%) and cells expressing human 3A4, 2E1 or 1B1 (80-85%). Likewise, cells expressing human 1A1 showed a higher contribution of alpha-HMP and COOH-P to the total metabolites (45%) than cells expressing the orthologous enzyme of the rat (3%). EP was metabolized at a higher rate and with modified regioselectivity compared with MP, although omega-hydroxylation of the side chain was not detected with the cell lines and only accounted for a small percent of the biotransformation by the microsomal preparations. The highest contributions of alpha-HEP to the total metabolites from EP were detected with the cells expressing human 1A1, 1B1 and 3A4 (38-51%). alpha-HEP accounted for 16% of the metabolites formed in the presence of human hepatic microsomes. Thus, benzylic hydroxylation is a major initial step in the metabolism of MP and EP. This pathway appears to be even more important in humans than in rats. Previously, we had shown that the second step of the activation, the sulfonation of alpha-HMP and alpha-HEP, is also efficiently catalysed by various forms of human sulfotransferases.
DOI: 10.1093/carcin/20.9.1777 PMID: 10469624 [Indexed for MEDLINE]
.Itaya, A., Kurahashi, A., Masuhara, H., Taniguchi, Y. and Kiguchi, M., 1990.
Fluorescence characterization of ablated polymeric materials: Poly (methyl methacrylate) doped with 1‐ethylpyrene.
ABSTRACT: Fluorescence spectra and rise as well as decay curves of 1‐ethylpyrene (EPy) in poly(methyl methacrylate) films changed using a XeCl (308‐nm) excimer laser as an ablation source. This phenomenon was observed not only for the ablated area but also for the masked region of about 20 μm around the ablated area and was attributed to the change of the dispersion condition of EPy. Effects of laser ablation upon properties of polymer films were elucidated by analyzing fluorescence dynamics using a microscope and under a total internal reflection condition.
Journal of applied physics, 67(5), pp.2240-2244.
. Smith, C.M. and Savage, P.E., 1992.
Reactions of polycyclic alkylaromatics. 4. Hydrogenolysis mechanisms in 1-alkylpyrene pyrolysis.
Energy & fuels, 6(2), pp.195-202.
. Armbruster, C., Knapp, M., Rechthaler, K., Schamschule, R., Parusel, A.B., Köhler, G. and Wehrmann, W., 1999.
Fluorescence properties of 1-heptanoylpyrene: a probe for hydrogen bonding in microaggregates and biological membranes.
Abstract: Fluorescence properties of 1-heptanoylpyrene in homogeneous solutions and incorporated into liposome membranes have been measured. The fluorescence intensity of the alkanoylpyrene is small in neat hydrocarbon solutions (Qf = 0.006) but increases with increasing solvent polarity. On the contrary, Qf of the 1-alkylpyrene is larger by a factor of 10 in a hydrocarbon solvent and decreases slightly in polar solvents. In alcohols the fluorescence yield of 1-heptanoylpyrene becomes considerably larger in comparison to a nonhydroxylic environment and nearly identical to that of heptylpyrene in the same solvent. The fluorescence spectra shift bathochromically in that polar environment. The fluorescence properties of 1-heptanoylpyrene incorporated in a liposome membrane indicate that the probe molecules are well embedded within the hydrophobic core of the bilayer. Semiempirical calculations were performed for 1-ethanoylpyrene and 1-ethylpyrene as model compounds in order to analyze the influence of solvent polarity and of hydrogen bonding on excited state energies and fluorescence properties of 1-acyl derivatives of pyrene. Hydrogen-bonding increases the energy gap between the lowest singlets, which are nearly degenerated, and the 3π*-n triplet and reduced consequently the intersystem crossing efficiency. But also a change in the sequence of the excited 1π*-π states is concluded from experimental data and should contribute to the increase of the fluorescence yield upon hydrogen bonding.
Journal of Photochemistry and Photobiology A: Chemistry, 125(1-3), pp.29-38.
. Vorobyova, O., Yekta, A., Winnik, M.A. and Lau, W., 1998.
Fluorescent probe studies of the association in an aqueous solution of a hydrophobically modified poly (ethylene oxide).
Abstract: We have used pyrene fluorescent probe experiments to study aqueous solutions of a poly(ethylene oxide) (PEO) of M = 35000 with C16H33 end groups. The end groups were attached by reaction of the PEO with hexadecyl isocyanate, and the polymer was then purified so that essentially all of the polymer in the sample contained 2.0 end groups/polymer molecule. The hydrophobic end groups of this polymer associate in water to form micelle-like structures which serve as solubilization sites for the pyrene molecules. Fluorescence decay profiles for both pyrene and 1-ethylpyrene were fitted to the Poisson quenching model to obtain the parameters n, the mean number of quenchers per micelle, and k, the pseudo-first-order rate constant for the quenching reaction in the micelle. While the data seem relatively well-behaved, we obtain different values for the end-group aggregation number (NR) for the two probes. For ethylpyrene, NR = 16 and k = 10.4 μs-1, while for pyrene, NR = 21 and k = 8.7 μs-1. Plots of n versus [Py] or [EtPy] are linear for various polymer concentrations, but exhibit a nonzero intercept in the limit of low quencher concentration. We examine a number of possible explanations for this behavior.
Macromolecules, 31(25), pp.8998-9007.